High-fat diet with antibiotic use linked to gut inflammation
Combining Western diet and antibiotic use is a pre- IBD risk factor
July 15, 2020
Science Daily/University of California - Davis Health
UC Davis researchers have found that combining a Western-style high-fat diet with antibiotic use significantly increases the risk of developing pre-inflammatory bowel disease (pre-IBD). The study, published July 14 in Cell Host and Microbe, suggests that this combination shuts down the energy factories (mitochondria) in cells of the colon lining, leading to gut inflammation.
Irritable bowel syndrome (IBS) affects approximately 11% of people worldwide. It is characterized by recurring episodes of abdominal pain, bloating and changes in bowel habits. IBS patients with mucosal inflammation and changes in the gut's microbial composition are considered pre-IBD.
Antibiotic usage with high-fat diet is a risk factor
The study included 43 healthy adults and 49 adult patients diagnosed with IBS. The researchers measured fecal calprotectin, a biomarker for intestinal inflammation, of participants. Elevated levels of fecal calprotectin indicated a pre-IBD condition. The study identified 19 patients with IBS as pre-IBD.
The researchers found that all participants who consumed high-fat diet and used antibiotics were at 8.6 times higher risk for having pre-IBD than those on low-fat diet and no recent history of antibiotic use. Participants with the highest fat consumption were about 2.8 times more likely to have pre-IBD than those with the lowest fat intake. A history of recent antibiotic usage alone was associated with 3.9 times higher likelihood of having pre-IBD.
"Our study found that a history of antibiotics in individuals consuming a high-fat diet was associated with the greatest risk for pre-IBD," said Andreas Bäumler, professor of medical microbiology and immunology and lead author on the study. "Until now, we didn't appreciate how different environmental risk factors can synergize to drive the disease."
Shutting the cell's powerhouse promotes gut microbial growth
Using mouse models, the study also tested the effect of high-fat diet and antibiotics use on the cells in the intestinal lining. It found that high-fat diet and antibiotics cooperate to disrupt the work of the cell's mitochondria, shutting its ability to burn oxygen. This disruption causes reduction in cell's oxygen consumption and leads to oxygen leakage into the gut.
The body's beneficial bacteria thrive in environments lacking oxygen such as the large intestine. Higher oxygen levels in the gut promote bacterial imbalances and inflammation. With the disruption in the gut environment, a vicious cycle of replacing the good bacteria with potentially harmful proinflammatory microbes that are more oxygen tolerant begins. This in turn leads to mucosal inflammation linked to pre-IBD conditions.
The study also identified 5-aminosalicylate (mesalazine), a drug that restarts the energy factories in the intestinal lining, as a potential treatment for pre-IBD.
"The best approach to a healthy gut is to get rid of the preferred sustenance of harmful microbes," Lee said. "Our study emphasized the importance of avoiding high fat food and abuse of antibiotics to avoid gut inflammation."
https://www.sciencedaily.com/releases/2020/07/200715142400.htm
Should you eat a low-gluten diet?
November 15, 2018
Science Daily/University of Copenhagen The Faculty of Health and Medical Sciences
When healthy people eat a low-gluten and fiber-rich diet compared with a high-gluten diet they experience less intestinal discomfort including less bloating which researchers show are due to changes of the composition and function of gut bacteria. The new study also shows a modest weight loss following low-gluten dieting. The researchers attribute the impact of diet on healthy adults more to change in composition of dietary fibers than gluten itself.
An increasing number of people choose a low-gluten diet, even though they are not allergic to the dietary substance. This trend has sparked public debate about whether or not low-gluten diets are recommendable for people without allergies. Now, researchers from University of Copenhagen among others have looked into just that.
In an intervention study of healthy Danish adults, reported today in Nature Communications, an international team of scientists shows that a low-gluten but fibre-rich diet changes the community of gut bacteria and decreases gastrointestinal discomfort such as bloating and is linked to a modest weight loss. The changes in intestinal comfort and body weight relate to changes in gut bacteria composition and function.
"We demonstrate that, in comparison with a high-gluten diet, a low-gluten, fibre-rich diet induces changes in the structure and function of the complex intestinal ecosystem of bacteria, reduces hydrogen exhalation, and leads to improvements in self-reported bloating. Moreover, we observed a modest weight loss, likely due to increased body combustion triggered by the altered gut bacterial functions," explains the leading principal investigator of the trial, Professor Oluf Pedersen, Novo Nordisk Foundation Center for Basic Metabolic Research at University of Copenhagen.
Change in dietary fibre composition seems to be the cause
The researchers undertook a randomised, controlled, cross-over trial involving 60 middle-aged healthy Danish adults with two eight week interventions comparing a low-gluten diet (2 g gluten per day) and a high-gluten diet (18 g gluten per day), separated by a washout period of at least six weeks with habitual diet (12 g gluten per day).
The two diets were balanced in number of calories and nutrients including the same amount of dietary fibres. However, the composition of fibres differed markedly between the two diets.
Based on their observations of altered food fermentation patterns of the gut bacteria, the researchers conclude that the effects of low-gluten dieting in healthy people may not be primarily due to reduced intake of gluten itself but rather to a change in dietary fibre composition by reducing fibres from wheat and rye and replacing them with fibres from vegetables, brown rice, corn, oat and quinoa.
No basis for change of diet recommendation yet
A low-gluten diet has previously been proposed to diminish gastrointestinal symptoms in patients with inflammatory bowel diseases and irritable bowel syndrome, disorders which occur in up to 20 percent of the general Western population.
The present study suggests that even some healthy individuals may prefer a low-gluten diet to combat intestinal discomfort or excess body weight.
"More long-term studies are definitely needed before any public health advice can be given to the general population. Especially, because we find dietary fibres -- not the absence of gluten alone -- to be the primary cause of the changes in intestinal discomfort and body weight. By now we think that our study is a wake-up call to the food industry. Gluten-free may not necessarily be the healthy choice many people think it is.
Most gluten-free food items available on the market today are massively deprived of dietary fibers and natural nutritional ingredients. Therefore, there is an obvious need for availability of fibre-enriched, nutritionally high-quality gluten-free food items which are fresh or minimally processed to consumers who prefer a low-gluten diet. Such initiatives may turn out to be key for alleviating gastro-intestinal discomfort and in addition to help facilitating weight control in the general population via modification of the gut microbiota," concludes senior lead investigator, Professor Oluf Pedersen.
https://www.sciencedaily.com/releases/2018/11/181115115340.htm