Wednesday January 29, 2020

Skin Exposure to UVB Light Alters Gut Bacteria For Good: Study

In a new clinical pilot study, researchers tested the effect of skin UVB exposure on the human gut microbiome

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UVB Light causes gut microbiome changes, via vitamin D production, it has so far been shown only in rodents. Pixabay

Skin exposure to ultra-violet B, also known as UVB Light radiation from the Sun can alter the gut microbiome in humans — possibly via vitamin D which can help explain the protective role of UVB in inflammatory diseases like Multiple Sclerosis and Inflammatory Bowel Disease.

Sun exposure, vitamin D levels and the mix of bacteria in our gut are each associated with risk of inflammatory conditions like MS and IBD, said scientists from University of British Columbia.

Exposure to UVB in sunlight is well-known to drive vitamin D production in the skin, and recent studies suggest that vitamin D alters the human gut microbiome.

However, that UVB, therefore, causes gut microbiome changes, via vitamin D production, has so far been shown only in rodents.

In a new clinical pilot study, researchers tested the effect of skin UVB exposure on the human gut microbiome.

Healthy female volunteers were given three, one-minute sessions of full-body UVB exposure in a single week.

Before and after treatment, stool samples were taken for analysis of gut bacteria – as well blood samples for vitamin D levels.

Skin UVB exposure significantly increased gut microbial diversity, but only in subjects who were not taking vitamin D supplements.

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Exposure to UVB in sunlight is well-known to drive vitamin D production in the skin, and recent studies suggest that vitamin D alters the human gut microbiome. Pixabay

“Prior to UVB exposure, these women had a less diverse and balanced gut microbiome than those taking regular vitamin D supplements,” reported Professor Bruce Vallance, who led the University of British Columbia study.

“UVB exposure boosted the richness and evenness of their microbiome to levels indistinguishable from the supplemented group, whose microbiome was not significantly changed”.

Published in Frontiers in Microbiology, the analysis suggests that vitamin D mediates the change — which could help explain the protective effect of UVB light in inflammatory diseases like MS and IBD.

The largest effect was an increase in the relative abundance of “Lachnospiraceae” bacteria after the UVB light exposures.

This indicates that vitamin D at least partly mediates UVB-induced gut microbiome changes.

The study is not designed to show the exact mechanism by which the microbiome changes occur, but both UVB and vitamin D are known to influence the immune system.

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Skin exposure to ultra-violet B, also known as UVB Light radiation from the Sun can alter the gut microbiome in humans. Pixabay

“It is likely that exposure to UVB light somehow alters the immune system in the skin initially, then more systemically, which in turn affects how favourable the intestinal environment is for the different bacteria,” suggests Vallance.

ALSO READ: Re-Assessing The Classical West: Two Emperors And A Sign

The results have implications for people who are undergoing UVB phototherapy, said scientists. (IANS)

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Here’s how Consuming High Fibre Diet Leads to Bloating

People who consume high fibre diets may experience bloating

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People who eat high fibre diets are more likely to experience bloating if their high fibre diet is protein-rich. Pixabay

People who eat high fibre diets are more likely to experience bloating if their high fibre diet is protein-rich as compared to carbohydrate-rich, according to a new study.

For the study, published in the journal Clinical and Translational Gastroenterology, the researchers from Johns Hopkins University analysed data from a clinical trial of high fibre diets.

“It’s possible that in this study, the protein-rich version of the diet caused more bloating because it caused more of a healthy shift in the composition of the microbiome,” said study co-senior author Noel Mueller from Johns Hopkins University in the US.

high fibre diets bloating
“It’s possible that in this study, the protein-rich version of the diet caused more bloating because it caused more of a healthy shift in the composition of the microbiome. Pixabay

“Notably, the protein in these diets was mostly from vegetable sources such as beans, legumes, and nuts,” Mueller added.

High-fibre diets are believed to cause bloating by boosting certain populations of healthful fibre-digesting gut bacteria species, which produce gas as a byproduct.

The findings thus also hint at a role for “macronutrients” such as carbs and proteins in modifying the gut bacteria population–the microbiome.

In the study, the researchers examined a dietary clinical trial that was conducted in 2003 and 2005 in Boston.

Known as the Optimal Macronutrient Intake Trial to Prevent Heart Disease (OmniHeart), it included 164 participants who had above-normal blood pressure.

They were assigned to three different diets over consecutive six-week periods separated by two-week “washout” intervals during which participants returned to regular eating habits.

high fibre diets bloating
High-fibre diets are believed to cause bloating by boosting certain populations of healthful fibre-digesting gut bacteria species, which produce gas as a byproduct. Pixabay

The diets were all considered high-fibre, low-sodium “DASH” diets, and had the same number of calories, but varied in their macronutrient emphases: a carbohydrate-rich version was, by calories, 58 per cent carbohydrate, 15 per cent protein, and 27 per cent fat; a plant-protein-rich version was 48 per cent carbs, 25 per cent protein, 27 per cent fat; and a fat-rich version was 48 per cent carbohydrate, 15 per cent protein, and 37 per cent fat.

The primary results of the OmniHeart trial, published in 2005, suggested that the plant-protein-rich and fat-rich diets were the most effective in reducing blood pressure and improving measures of blood cholesterol.

In their new analysis of this data, they examined how participants’ reports of bloating–which were among the secondary data collected in that trial–varied as participants ate the three OmniHeart diets.

A key finding was that the prevalence of bloating went from 18 per cent before the diets to 24, 33, and 30 per cent, respectively, on the carb-, protein-, and fat-rich diets–indicating that these high fibre diets did indeed appear to increase bloating.

Also Read- Eating Walnuts May Help Slow Cognitive Decline: Study

The researchers also analysed the relative changes among the diets, and linked the protein-rich diet to a significantly greater chance of bloating–roughly 40 percent greater–in comparison with the carb-rich diet.

The results suggest that substituting high quality carb calories, such as whole grain, for protein calories might reduce bloating for those on high fiber diets, making such diets more tolerable. (IANS)