Differences between male and female fat tissue, and health

Mouse study provides important clue as to how females stay healthier than males, even as body fat increases

October 23, 2018

Science Daily/York University

In a new study, researchers found that the abdominal fat on female mice had more blood vessels than the fat on male mice, and that this protected the health of the female mice as they gained fat from eating a high-fat diet.

Published today in Frontiers in Physiology -- Vascular Physiology, the research focuses on the differences between abdominal fat in obese male and female mice. A team of researchers under the direction of Professor Tara Haas found that the abdominal fat on female mice had more blood vessels than the fat on male mice, and that this protected the health of the female mice as they gained fat from eating a high-fat diet.

Males and females develop fat tissue differently and also differ in susceptibility to cardiovascular disease, insulin resistance and diabetes. However, the underlying biology behind why fat tissue in females is more protective against these conditions was not well understood, says Haas, a professor in the School of Kinesiology and Health Science, Faculty of Health.

Blood vessels are critical for maintaining healthy fat tissue by ensuring that the expanding fat cells are supplied with enough oxygen and nutrients, so the researchers looked at whether the abilities of the fat tissue to grow blood vessels and maintain healthy fat tissue would be different between males and females.

"We found that female mice have a higher number of blood vessels in their fat than males, and that females increase the number of blood vessels as they are fed a high fat diet, while males do not. We concluded that this response enabled females to maintain healthier fat and better insulin sensitivity," says Haas.

Martina Rudnicki, a York post-doctoral associate and first author of the study, pointed out that the study was unique because it focused on the differences in male and female fat tissue in the abdominal area. Although fat accumulates in different regions of the body, it is abdominal fat that is closely linked with increased risk of developing diabetes, particularly in males. So, the fact that females grow new blood vessels in this abdominal fat during weight gain may exert a health advantage for females.

The sex differences in the fundamental cellular processes that regulate the growth of blood vessels were unappreciated in the past, said Haas. It is important to understand them because they may contribute to an individual's susceptibility to develop serious obesity-related health complications such as diabetes, heart disease and cancer, ultimately impacting the health of more than 5.3 million Canadian adults.

The research team plans to confirm these findings in human samples. While it is clear that females also develop health problems with obesity, the fact that there was such a difference in the vascularization in male and female fat may mean it would be more effective to have different treatments for males and females.

https://www.sciencedaily.com/releases/2018/10/181023130529.htm

Gut microbiota of infants predicts obesity in children

October 23, 2018

Science Daily/American Society for Microbiology

Evaluating the gut microbiota of infants may help identify children who are at risk for becoming overweight or obese. The research revealed that gut microbiota composition at two years of life is associated with body mass index (BMI) at age 12. In addition, the BMI at age two was not significantly higher in children who later became overweight/obese, indicating that gut microbiota composition may be the earliest warning sign for detecting obesity.

"Our study provides more evidence that the gut microbiota might be playing a role in later obesity," said lead author Maggie Stanislawski, PhD, who is a research associate at the LEAD Center, University of Colorado Anschutz Medical Campus, Colorado School of Public Health, Aurora, Colorado. "If our findings can be confirmed by other studies, the gut microbiota might play an important part of the obesity prediction algorithm, to identify at-risk kids early in life, before they start to gain any excess weight that might put them at risk for later obesity."

Prior to this study, a growing body of evidence has demonstrated that the gut microbiota plays a role in obesity, and there is some evidence that the role might be causal. To shed more light on the issue, the University of Colorado researchers collaborated with Merete Eggesbø, MD, PhD, who leads the NoMIC study at the Norwegian Institute of Public Health in Oslo, and analyzed data from 165 infants who had BMI measured at 12 years.

The NoMIC study began in 2002 as one of the earliest birth cohorts in the world to investigate the early life gut microbiome and includes roughly 550 kids who are now teenagers. The study recruited moms and infants in the hospital at the time of delivery. At 12 years of age, 20% of the 165 children in the study cohort were overweight or obese.

The researchers compared the BMI at age 12 with gut microbiota samples from six time points throughout their childhood, at day 4, day 10, one month, four months, one year, and two years. They performed 16s rRNA gene sequencing on the gut microbiota samples. "We looked at whether there were specific taxa that were predictive of later BMI at each time point," said Dr. Stanislawski.

The researchers found qualitative differences in the composition of children's gut microbiota at day ten and at two years that were associated with BMI z-scores at age 12. BMI z-scores are measures of relative weight adjusted for child age and sex. They also examined how much of the variation in childhood BMI z-scores was explained by the early gut microbiota taxa.

"At the early time points, there was somewhat of a relationship between the gut microbiota taxa and later BMI, but the relationship was much stronger as the kids got older," said Dr. Stanislawski. "At one year, it was stronger than the earlier time points. At two years, it was the strongest. We found this very interesting because, at two years, there wasn't any obvious phenotype in terms of whether or not the kids were going to become obese. Kids who became obese later in life didn't have high BMI z-scores at age 2. The findings suggest that the gut microbiota phenotype was present before any overt sign of overweight or obesity. Since the gut microbiota is influenced by diet, this association could also reflect dietary choices that are precursors to obesity."

Dr. Stanislawski said the study was limited in that the entire cohort was of Norwegian descent. This research, she said, needs to be repeated in other cohorts, but if replicated, it may lead to a new tool to identify kids at risk for developing obesity. "It is better to identify at-risk kids early. It is easier to prevent obesity than to reverse it," said Dr. Stanislawski. "It's possible that if we follow up some of these findings in the lab, it will reveal more about the pathophysiology of obesity as well."

The study also exposed a potential health caution. The researchers found that some gut microbes that are generally thought to be healthy in both children and adults were associated with higher childhood BMI. This highlights that we do not fully understand the dynamics of the gut colonization process.

"When I was pregnant, my doctor suggested giving the baby probiotics every day, and I think a lot of people are giving their infants probiotics," said Dr. Stanislawski. "However, it might not be the best idea to give babies the same types of bacteria every day, particularly in very early life when overloading the gut with one or two strains may prevent colonization with other types of important bacteria." She pointed out that one way to improve the gut microbiota in kids and adults is to eat a well-balanced diet with lots of different types of vegetables and fiber, so there are lots of things feeding the gut microbiota.

Future research will focus on further examining the colonization process in relation to other markers of metabolic health in children. "We will focus on the temporal dynamics of first two years," said Dr. Stanislawski.

https://www.sciencedaily.com/releases/2018/10/181023085640.htm

Effects of a high-fat diet may be passed on for three generations

October 12, 2018

Science Daily/BioMed Central

A high-fat diet in female mice affects their offspring's obesity, insulin resistance and addictive-like behaviors for three generations, according to a new study.

Researchers at ETH Zurich, Switzerland showed that second generation offspring -- grandchildren of mice that had consumed a high-fat diet before, during and after pregnancy showed addictive-like behaviors such as increased sensitivity and preference for drugs, as well as characteristics of obesity, including changes in their metabolism. In third generation offspring (the great grandchildren), the authors observed differences between males and females, with only females showing addictive-like behaviors and only males showing obesity characteristics.

This was the case although the original female mice themselves never became obese and although none of the following generations consumed a high-fat diet.

Dr Daria Peleg-Raibstein, the corresponding author said: "Most studies so far have only looked at the second generation or followed the long-term effects of obesity and diabetes on the immediate offspring. This study is the first to look at the effects of maternal overeating up until the third generation in the context of addiction as well as obesity."

The authors investigated these effects specifically for transmission via male offspring up until, and including, the third generation. To do so, they fed female mice either high-fat diet or a standard laboratory diet for nine weeks -- pre-mating, during pregnancy and during lactation. Their male offspring were then mated with females that had been fed a standard laboratory diet to generate the second-generation offspring. The male offspring of these mice was again mated with females that had been fed a standard laboratory diet to generate the third-generation offspring.

The authors measured body weight, insulin sensitivity, metabolic rates, and blood plasma parameters such as insulin and cholesterol in second and third-generation offspring. In behavioral experiments they investigated if the mice chose a high-fat over a standard laboratory diet or an alcohol solution over water, as well as their activity levels after exposure to amphetamines. They did this to better understand if a maternal high-fat diet had an effect on obesity, overeating and drug sensitivity in subsequent generations.

Dr Peleg-Raibstein said: "To combat the current obesity epidemic, it is important to identify the underlying mechanisms and to find ways for early prevention. The research could help improve health advice and education for pregnant and breastfeeding couples and give their children, grandchildren and great-grandchildren a better chance of a healthy lifestyle. It may also provide a way of identifying risk factors for how people develop obesity and addiction and suggest early interventions for at-risk groups."

Dr Peleg-Raibstein added: "It is quite a leap to apply conclusions from mouse studies to humans, but studying effects of maternal over-eating is almost impossible to do in people because there are so many confounding factors, such as socio-economic background, the parents' food preferences or their existing health conditions. The mouse model allowed us to study the effects of a high-fat diet on subsequent generations without these factors."

Further studies are needed to determine the molecular mechanism by which the effects of a female high-fat diet may be passed on to following generations.

https://www.sciencedaily.com/releases/2018/10/181012082710.htm

Study firms up diet and depression link

October 10, 2018

Science Daily/James Cook University

In an unusual experiment, researchers have found that among Torres Strait Islander people the amount of fish and processed food eaten is related to depression.

A JCU research team led by Professors Zoltan Sarnyai and Robyn McDermott looked at the link between depression and diet on a Torres Strait island, where fast food is available, and on a more isolated island, which has no fast food outlets.

Dr Maximus Berger, the lead author of the study, said the team interviewed about 100 people on both islands.

"We asked them about their diet, screened them for their levels of depression and took blood samples. As you'd expect, people on the more isolated island with no fast food outlets reported significantly higher seafood consumption and lower take-away food consumption compared with people on the other island," he said.

The researchers identified nineteen people as having moderate to severe depressive symptoms: sixteen were from the island where fast food is readily available, but only three from the other island.

"People with major depressive symptoms were both younger and had higher take-away food consumption," said Dr Berger.

The researchers analysed the blood samples in collaboration with researchers at the University of Adelaide and found differences between the levels of two fatty acids in people who lived on the respective islands.

"The level of the fatty acid associated with depression and found in many take-away foods was higher in people living on the island with ready access to fast food, the level of the fatty acid associated with protection against depression and found in seafood was higher on the other island," said Dr Berger.

He said it was important to remember that contemporary Western diets have an abundance of the depression-linked fatty acid (n-6 PUFA) and a relative lack of the depression-fighting fatty acid (n-3 LCPUFA).

"In countries with a traditional diet, the ratio of n-6 to n-3 is 1:1, in industrialised countries it's 20:1," he said.

Professor Sarnyai said depression affects about one in seven people at some point in their lives and Aboriginal and Torres Strait Islander people are disproportionately affected by psychological distress and mental ill-health compared with the general population.

"Depression is complex, it's also linked to social and environmental factors so there will be no silver bullet cure, but our data suggests that a diet that is rich in n-3 LCPUFA as provided by seafood and low in n-6 PUFA as found in many take-away foods may be beneficial," he said.

Professor Sarnyai said with the currently available data it was premature to conclude that diet can have a lasting impact on depression risk but called for more effort to be put into providing access to healthy food in rural and remote communities.

"It should be a priority and may be beneficial not only to physical health but also to mental health and wellbeing," he said.

https://www.sciencedaily.com/releases/2018/10/181010093645.htm

Vitamin D supplements may promote weight loss in obese children

September 27, 2018

Science Daily/European Society for Paediatric Endocrinology

Vitamin D supplements may promote weight loss and reduce risk factors for future heart and metabolic disease in overweight and obese children, according to new research. These findings indicate that simple vitamin D supplementation may be part of an effective strategy to tackle childhood obesity and reduce the risk of serious health problems, such as heart disease, in adulthood.

Obesity in childhood and adolescence represents a major health problem worldwide, which leads to the development of expensive, serious and debilitating complications, including heart disease and diabetes, in later life. Although vitamin D deficiency is typically associated with impaired bone health, in recent years it has been increasingly linked with increased body fat accumulation and obesity, with the precise nature of this relationship currently under intense investigation by researchers. However, the effect of vitamin D supplementation on the weight and health of obese children and adolescents had not yet been investigated.

In this study, Dr. Christos Giannios, Professor Evangelia Charmandari and colleagues at the University of Athens Medical School and the 'Aghia Sophia' Children's Hospital in Athens, assessed 232 obese children and adolescents over 12 months, with 117 randomly assigned to receive vitamin D supplementation, in accordance with the Endocrine Society's guidelines on treatment and prevention of deficiency. Levels of vitamin D, body fat, and blood markers of liver function and heart health were assessed at the start of the study and 12 months later. The study reported that children given vitamin D supplements had significantly lower body mass index, body fat and improved cholesterol levels after 12 months of supplementation.

"These findings suggest that simple vitamin D supplementation may reduce the risk of overweight and obese children developing serious heart and metabolic complications in later life," says lead researcher Prof Charmandari.

The team now plan to investigate the effects of vitamin D supplementation on the health of obese children and adolescents that already have unhealthy conditions, such as high blood pressure, high blood glucose and high cholesterol, all of which increase the risk of heart disease, stroke and diabetes.

Prof Charmandari cautions, "Although these initial findings indicate that vitamin D could be used in the treatment of obesity, there remains a lack of evidence on the safety and long-term effects of supplementation, particularly if there is no vitamin D deficiency. However, if your child is overweight or obese I recommend that you consult your primary care physician for advice, and consider having their vitamin D levels tested."

https://www.sciencedaily.com/releases/2018/09/180927215656.htm

Overweight pregnant women can safely cut calories, restrict weight gain

Healthier for mom and baby to control mom's weight gain during pregnancy

September 24, 2018

Science Daily/Northwestern University

With proper nutrition guidance, it is safe and feasible to restrict weight gain in obese and overweight pregnant women, a new study shows.

Being obese or overweight during pregnancy can result in serious health problems for the mother and child. Obstetricians are often reluctant to recommend restricted weight gain for pregnant women due to safety concerns for the baby and lack of time and tools to safely guide women in their weight control efforts.

A new Northwestern Medicine study shows with proper nutrition guidance it is safe and feasible to restrict weight gain in obese and overweight pregnant women. The obese and overweight women in the study gained five pounds less during their pregnancy than those in the control group. Their babies were born in the normal weight range.

The approach included nutritional counseling on a healthy diet and lifestyle as supported by a commercially available smartphone diet app, with ongoing coaching via the phone and online.

"We need to help these women, who make up the majority of pregnancies in the U.S, leverage this unique opportunity during their pregnancy to adopt a healthier diet and lifestyle plan that they can follow throughout pregnancy and, hopefully, post-partum," said lead study author Linda Van Horn, professor of preventive medicine at Northwestern University Feinberg School of Medicine. "These results show promise in harnessing modern technology to help a mom achieve those goals."

The majority of U.S. women of reproductive age are overweight or obese, and the risk of excess gestational weight gain is higher for them than women of healthy weight. Among the risks for women and their babies: diabetes, preeclampsia, hypertension and birth defects.

Van Horn, along with obstetrician colleague Dr. Alan Peaceman, developed and led the study, called MOMFIT (Maternal Offspring Metabolics: Family Intervention Trial). It was part of the Lifestyle Interventions for Expectant Moms (LIFE-Moms) Consortium, a National Institutes of Health (NIH)-supported research project, with each study implementing separate interventions.

The Northwestern study was novel because it concentrated on improving diet quality and healthy lifestyle in the moms using modern tools and focused on potential maternal fetal nutrition advantages that could have lifelong benefits, Van Horn said.

The study will be published Sept. 24 in the American Journal of Preventive Medicine.

This is believed to be the first study of obese and overweight pregnant women using a technologically advanced, commercially available weight-loss smartphone app to test the effects of a specially tailored diet combined with modest physical activity.

Existing commercial weight control technologies target non-pregnant women and don't address prenatal energy and nutrient needs, the authors said. Most commercial apps are designed to support weight loss. During pregnancy, weight gain is anticipated and appropriate, but it should be curtailed in overweight and obese women.

"MOMFIT demonstrates the feasibility of counseling pregnant women in healthy diet and lifestyle behaviors through nutrition coaching using modern technology," Van Horn said. "Applying this approach in a clinical setting could help women achieve recommended weight-gain goals during pregnancy and improve postpartum lifestyle behaviors for the whole family."

One unusual outcome of the trial was a higher rate of cesarean sections for the women in the intervention group. Researchers are investigating possible contributors to this finding.

Will MOMFIT kids have less risk of developing obesity?

"The next big question is whether the children born to moms who restricted their weight gain will have a reduced risk of becoming obese themselves compared to children whose moms were in the control group," Van Horn said.

Children born to overweight and obese moms have more than a 50 percent chance of becoming overweight themselves. If both parents are overweight or obese, this risk can increase to more than 70 percent, according to epidemiological data.

The difference in the children's obesity risk won't be evident until they are three, four and five years old, which is when weight trajectories start to separate. Van Horn and colleagues have recently launched a new study -- KIDFIT -- to monitor the children of the women in her MOMFIT study and determine whether prenatal and/or postpartum diet and lifestyle counseling can help these children lower their risk of obesity.

Rebooting the whole family's diet

The study's goal was not weight loss. "Weight loss during pregnancy is not encouraged. Rather, we aimed for controlled weight gain by developing healthy diet habits and increasing physical activity that could be sustained long term.

"The overarching goal of MOMFIT was to help the mom make these changes while she was still pregnant, a time when many women are more motivated to do what is right for their babies, and then maintain these new behaviors and become a role model for the family and better informed about how to feed them," Van Horn said.

"The perpetuation of obesity is a never-ending cycle. We're attempting to interrupt that cycle and successfully influence the risk for developing pediatric obesity starting in utero and -- with additional follow up -- protect that child from adopting that parental heritage in the family home."

Fewer participants in the intervention group, 68.6 percent versus 85 percent, exceeded the National Academy of Medicine recommendations for pregnancy weight gain for obese and overweight women, which is limited to 11 to 25 pounds compared to 25 to 35 pounds for women of healthy weight. This is important evidence demonstrating the challenges of encouraging pregnant women to adhere to recommended diet and activity levels at a time when emotional-eating and reluctance to exercise tend to increase.

How the study worked

MOMFIT studied 281 ethnically diverse overweight or obese women ages 18 to 45, who were divided into the intervention or control group. Women in the intervention group met with a nutritionist who calculated the appropriate amount of calories for each participant and counseled her on a DASH-type diet -- higher in fruits, vegetables, whole grains, nuts, fish and lean protein. It was modified to the restricted weight gain recommendations for each participant.

The DASH (Diet Approach to Stopping Hypertension) eating pattern is ideally suited to pregnancy, providing a pregnant woman with the calcium, potassium and protein she needs without the salt, sugar and saturated fat that she does not need, Van Horn said.

The women were also encouraged to walk at least 30 minutes or take 10,000 steps per day. The nutrition coach tracked each woman's weight gain, food intake and exercise. Telephone, text message prompts and e-mail reminders encouraged women to adhere to the program.

"It was technologically convenient yet strategic and nutritionally individualized," Van Horn said. "MOMFIT took a precision medicine approach to healthy eating utilizing a commercially available product."

Women tracked their food intake with the Lose It! app. Participants were also encouraged to sleep seven to nine hours daily, because sleep deprivation hampers metabolism and contributes to weight gain.

https://www.sciencedaily.com/releases/2018/09/180924084332.htm

Anti-inflammatory protein promotes healthy gut bacteria to curb obesity

New approach to weight loss and diabetes prevention published

September 19, 2018

Science Daily/University of North Carolina Health Care

Scientists have discovered that the anti-inflammatory protein NLRP12 normally helps protect mice against obesity and insulin resistance when they are fed a high-fat diet. The researchers also reported that the NLRP12 gene is underactive in people who are obese, making it a potential therapeutic target for treating obesity and diabetes, both of which are risk factors for cardiovascular disease and other serious conditions.

The study, published in Cell Host & Microbe, showed that NLRP12's anti-inflammatory effect promotes the growth of a "good" family of gut-dwelling bacteria, called Lachnospiraceae, that produce small molecules butyrate and propionate, which in turn promote gut health and protect mice against obesity and insulin resistance.

"Obesity is influenced by inflammation, not just by overeating and lack of exercise, and this study suggests that reducing inflammation promotes 'good' bacteria that can help maintain a healthy weight," said study senior author Jenny P-Y Ting, PhD, a William R. Kenan, Jr. Distinguished Professor of Genetics. "In mice, we showed that NLRP12 reduces inflammation in the gut and in adipose fat tissues. Although a direct causal effect is difficult to show in humans, our collaborators did help us show there are reduced expression levels of NLRP12 in individuals who are considered obese."

In humans, NLRP12 is produced by several types of immune cells and appears to function as a brake on excessive inflammation. Ting and colleagues in recent years have published studies showing that mice lacking the NLRP12 gene are highly susceptible to excessive inflammation, including experimental colon inflammation (colitis) and associated colon cancer.

In recent years, researchers have found evidence that inflammation in the gut and in where fat is deposited promotes obesity. About 40 percent of adults and 20 percent of children and teens age 2 to 19 in the United States are considered obese, according to recent government estimates. Being obese or even overweight can lead to a host of other conditions, including heart disease, stroke, cancers, and diabetes. Ting and colleagues in this study therefore sought to determine whether mice lacking the NLRP12 gene are more susceptible to obesity. The findings showed that they are.

The scientists fed mice that lacked the NLRP12 gene (NLRP12-knockout mice) and ordinary mice a high-fat diet for several months. The NLRP12-knockout mice ate and drank no more than their healthy cousins but accumulated significantly more fat and became heavier. The knockout mice also showed signs of insulin resistance, which involves a reduced ability to clear glucose from the bloodstream and tends to follow the development of obesity.

The absence of NLRP12 in these mice led to increased signs of inflammation in the gut and in fat deposits, but it wasn't clear how this led to extra weight gain until the researchers moved the animals from one facility to another. Following standard safety protocols to prevent disease spread, the researchers dosed the mice with antibiotics before the move.

"We noticed that the mice treated with antibiotics gained less weight than the mice that stayed in the old facility," said study co-first author Agnieszka Truax, PhD, a postdoctoral researcher in the Ting lab during the study. "That led us to suspect that gut bacteria were involved in promoting obesity."

Further tests showed that when NLRP12-knockout mice were kept in a bacteria-free condition, the mice did not gain weight because there were no bacteria. The deficiency of NLRP12 didn't matter as much. This suggested that "bad" bacteria had been driving the excess weight gain during a high-fat diet.

Remarkably, the knockout mice were also protected from excess weight gain when they were co-housed with control mice, hinting that "good" bacteria from the control mice were getting into them and helping to protect them.

Scientists have known that high-fat diets, as compared to low-fat diets, tend to reduce the diversity of bacterial species in the gut by suppressing some species and allowing a few others to proliferate abnormally. The UNC researchers confirmed this in their high-fat-eating mice, and they observed that the loss of bacterial diversity was much worse in the Nlrp12-knockout mice.

The experiments suggested that inflammation caused by a high-fat diet and worsened by the absence of NLRP12 was a major cause of this shift. Killing off rival bacterial species allowed a sharp rise in the levels of a bacterial family called Erysipelotrichaceae. These microbes became more prominent as gut inflammation worsened and exacerbated the weight-gain from a high-fat diet when put into the guts of otherwise germ-free mice.

By contrast, the Lachnospiraceae family of bacteria, which tended to die off in mice fed a high-fat diet, appeared to be highly beneficial. The researchers fed Lachnospiraceae to NLRP12-knockout mice prior to and during three weeks of high-fat eating and found that these "good" bacteria reduced gut inflammation, eliminated the hegemony of harmful Erysipelotrichaceae, and promoted more bacterial diversity. The Lachnospiraceae also significantly protected the animals against obesity and associated insulin-resistance.

"All the inflammatory and metabolic changes we had seen in the NLRP12-knockout mice during a high-fat diet were essentially reversed when we re-supplied Lachnospiraceae," Truax said.

Lachnospiraceae contain enzymes that convert carbs and fiber into small molecules called short-chain fatty acids (SCFAs). The scientists observed that two in particular, butyrate and propionate, appeared in significantly greater abundance when Lachnospiracea levels rose. Butyrate and propionate are known to have anti-inflammatory properties that promote gut health. The UNC team fed these SCFAs to the NLRP12-knockout mice and found that SCFAs protected the animals from the absence of NLRP12 just as well as the Lachnospiraceae had done.

Butyrate, propionate, and other SCFAs are already widely available as health supplements. But are these results in mice relevant to humans? A further test suggested that they are. Collaborating scientists Mihai Netea, MD, PhD, and Rinke Stienstra, PhD, from Radboud University Medical Center in the Netherlands examined fat cells from obese human patients and observed that the higher the measure of obesity -- the body-mass index -- the lower the activity of the NLRP12 gene tended to be.

Thus, treating people with "good" bacteria or the beneficial SCFAs they produce might one day be a relatively inexpensive strategy to combat obesity as well as diabetes and other obesity-driven conditions. Ting and colleagues plan to continue their investigations in that direction.

https://www.sciencedaily.com/releases/2018/09/180919133616.htm

Young children's oral bacteria may predict obesity

September 19, 2018

Science Daily/Penn State

Weight gain during early childhood is related to the composition of oral bacteria of two-year-old children, suggesting this understudied aspect of a children's collection of microorganisms could serve as an early indicator for childhood obesity.

Weight gain trajectories in early childhood are related to the composition of oral bacteria of two-year-old children, suggesting that this understudied aspect of a child's microbiota -- the collection of microorganisms, including beneficial bacteria, residing in the mouth -- could serve as an early indicator for childhood obesity. A study describing the results appears September 19 in the journal Scientific Reports.

"One in three children in the United States is overweight or obese," said Kateryna Makova, Pentz Professor of Biology and senior author of the paper. "If we can find early indicators of obesity in young children, we can help parents and physicians take preventive measures."

The study is part of a larger project with researchers and clinicians at the Penn State Milton S. Hershey Medical Center called INSIGHT, led by Ian Paul, professor of pediatrics at the Medical Center, and Leann Birch, professor of foods and nutrition at the University of Georgia. The INSIGHT trial includes nearly 300 children and tests whether a responsive parenting intervention during a child's early life can prevent the development of obesity. It is also designed to identify biological and social risk factors for obesity.

"In this study, we show that a child's oral microbiota at two years of age is related to their weight gain over their first two years after birth," said Makova.

The human digestive tract is filled with a diverse array of microorganisms, including beneficial bacteria, that help ensure proper digestion and support the immune system. This "microbiota" shifts as a person's diet changes and can vary greatly among individuals. Variation in gut microbiota has been linked to obesity in some adults and adolescents, but the potential relationship between oral microbiota and weight gain in children had not been explored prior to this study.

"The oral microbiota is usually studied in relation to periodontal disease, and periodontal disease has in some cases been linked to obesity," said Sarah Craig, a postdoctoral scholar in biology at Penn State and first author of the paper. "Here, we explored any potential direct associations between the oral microbiota and child weight gain. Rather than simply noting whether a child was overweight at the age of two, we used growth curves from their first two years after birth, which provides a more complete picture of how the child is growing. This approach is highly innovative for a study of this kind, and gives greater statistical power to detect relationships."

Among 226 children from central Pennsylvania, the oral microbiota of those with rapid infant weight gain -- a strong risk factor for childhood obesity -- was less diverse, meaning it contained fewer groups of bacteria. These children also had a higher ratio of Firmicutes to Bacteroidetes, two of the most common bacteria groups found in the human microbiota.

"A healthy person usually has a lot of different bacteria within their gut microbiota," said Craig. "This high diversity helps protect against inflammation or harmful bacteria and is important for the stability of digestion in the face of changes to diet or environment. There's also a certain balance of these two common bacteria groups, Firmicutes and Bacteroidetes, that tends to work best under normal healthy conditions, and disruptions to that balance could lead to dysregulation in digestion."

Lower diversity and higher Firmicutes to Bacteroidetes (F:B) ratio in gut microbiota are sometimes observed as a characteristic of adults and adolescents with obesity. However, the researchers did not see a relationship of weight gain with either of these measures in gut microbiota of two-year-olds, suggesting that the gut microbiota may not be completely established at two years of age and may still be undergoing many changes.

"There are usually dramatic changes to an individual's microbiota as they develop during early childhood," said Makova. "Our results suggest that signatures of obesity may be established earlier in oral microbiota than in gut microbiota. If we can confirm this in other groups of children outside of Pennsylvania, we may be able to develop a test of oral microbiota that could be used in clinical care to identify children who are at risk for developing obesity. This is particularly exciting because oral samples are easier to obtain than those from the gut, which require fecal samples."

Interestingly, weight gain in children was also related to diversity of their mother's oral microbiota. This could reflect a genetic predisposition of the mother and child to having a similar microbiota, or the mother and child having a similar diet and environment.

"It could be a simple explanation like a shared diet or genetics, but it might also be related to obesity," said Makova. "We don't know for sure yet, but if there is an oral microbiome signature linked to the dynamics of weight gain in early childhood, there is a particular urgency to understand it. Now we are using additional techniques to look at specific species of bacteria -- rather than larger taxonomic groups of bacteria -- in both the mothers and children to see whether specific bacteria species influence weight gain and the risk of obesity."

https://www.sciencedaily.com/releases/2018/09/180919083508.htm

Strength-based exercises could help child obesity fight

September 19, 2018

Science Daily/University of Edinburgh

Encouraging young people to do strength-based exercises -- such as squats, push ups and lunges -- could play a key role in tackling child obesity, research suggests.

Taking part in exercises that cause muscles to contract, and strengthen muscles and bones, was found to reduce children's body fat percentage.

The findings also suggests an increase in muscle mass -- gained from strength-based exercises -- could help boost children's metabolism and energy levels.

The effects were small but meaningful, prompting calls for further research to investigate how resistance training could treat and prevent the growing issue of child obesity.

Researchers at the Universities of Edinburgh and Dundee examined the findings from a number of studies that explored effects of resistance training on body weight for children aged nine to 18 years.

They found that resistance training decreased body fat, but had no overall effect on other measures, including lean muscle mass, body mass index and waist circumference.

This is the most extensive review so far of resistance training's impact on young people.

Research from 18 studies across eight countries was examined, including the US, Australia, and Japan.

Helen Collins, a PhD student at the University of Edinburgh and Sport and Exercise Scientist at the University of Dundee, said the results show the positive effect resistance training can have on maintaining a healthy weight and reducing body fat for young people.

"Treatment, and more importantly, prevention, of child obesity is a growing concern. Our findings highlight the need for more robust research into the role strength-based exercises can play in helping everyone make healthy life choices and be more physically active."

https://www.sciencedaily.com/releases/2018/09/180919083145.htm

Either too much or too little weight gain during pregnancy is associated with adverse outcomes in children aged 7 years

September 17, 2018

Science Daily/Diabetologia

New research shows that if a woman gains either too much or too little weight during pregnancy, there are adverse effects in children at 7 years of age.

There have been various studies on the effects of weight gain during pregnancy (gestational weight gain or GWG), however data on the metabolic effects in the children subsequently born have not been comprehensively studied. This study aims to evaluate the relationship between GWG and cardiometabolic risk in offspring aged 7 years.

The study included a total of 905 mother-child pairs who were enrolled in the follow-up visit of the multicentre Hyperglycemia and Adverse Pregnancy Outcome study, at the study centre in Hong Kong. Women were classified as having gained weight below, within or exceeding the 2009 Institute of Medicine (IOM) guidelines. Also factored in the study were standardised GWG values based on pre-pregnancy body-mass index (BMI).

Among the 905 women, the mean pre-pregnancy BMI was 21 kg/m2, the total prevalence of overweight and/or obese participants was 8.3%. The weight change from pre-pregnancy to delivery was 15kg on average, with 17% having gained weight below, 42% having gained weight within and 41% having gained weight exceeding the IOM recommendation.

Independent of pre-pregnancy BMI, gestational hyperglycaemia and other confounders, women who gained more weight than the IOM recommendation had offspring with larger body size at age 7 years, and increased odds of higher body fat, high blood pressure and poor blood sugar control, while women who gained less than the recommendation had offspring with increased risks of high blood pressure and poor blood sugar control at 7 years of age, compared with those who gained weight within the recommended range.

The authors say: "We found evidence of linkage between GWG and several cardiometabolic risk factors in the offspring aged 7 years, independently of maternal BMI prior to pregnancy and glucose level during pregnancy. These findings have important implications for both prevention and treatment. There is a need for greater awareness and monitoring of weight gain during pregnancy. Pregnancy might be a potential window of opportunity for intervention through modifiable behaviours, including maternal nutrition and physical activity."

However, they add: "Although limiting excessive GWG may help minimise the intergenerational cycle of obesity, the benefits of lower weight gain must be balanced against other cardiometabolic risks -- such as high blood pressure and poorer blood sugar control -- and risk of stunted growth in the offspring if GWG is inadequate."

They conclude: "Long-term follow-up of these children is necessary to evaluate the effect of maternal GWG on cardiometabolic risk in adolescence and adulthood."

https://www.sciencedaily.com/releases/2018/09/180917191907.htm