Short-term intervention in daily fiber consumption can dramatically alter gut microorganisms and nutrition, according to a study led by University of California, Irvine researchers. The research was recently published by the American Society for Microbiology.
Dietary fiber includes resistant carbohydrates found in fruits, vegetables and whole grains. Fiber persists in our digestive system, and while not easily digested by humans, our gut bacteria can take root in short-chain fatty acids and other byproducts that are vital to human health.
Currently, the average North American person eats less than 50 percent of the recommended dietary fiber levels due to reduced consumption of plant-based foods, due to the fact that food is processed has become widespread. A lower fiber diet is a concern for health officials as low consumption of dietary fiber may be linked to diseases such as type II diabetes and colon cancer.
In addition, new studies have begun to show how microbial gut changes can have an indirect impact on human health. Thus, a better understanding of the role of dietary fiber on the basis of gut microbiota could provide insights into the management of diseases associated with the gut microbiome.
The lack of fiber intake in the industrial world is depleting our gut microbes, with important health consequences that may be associated with an increase in colorectal cancer, autoimmune diseases and even a decrease in vaccine efficacy and response to cancer immunotherapy, “
Katrine Whiteson, Associate Professor of Molecular Biology & Biochemistry, University of California, Irvine
Whiteson co-leads the UCI Microbiome Initiative.
To determine whether short-term dietary fiber boosting could alter gut microbial diversity and metabolite production, a research team led by UCI Whiteson Microbiome Initiative co-leaders and Jennifer Martiny, professor of ecology & biology evolutionary studies, with Julia Massimelli Sewall, assistant. teaching professor, he implemented a two-week diet intervention during an undergraduate biology course at UCI.
The students who participated in the study received 10 high-fiber processed foods per week for two weeks. During the period, they collected samples to monitor their gut microbial status before and after the intervention. Students also recorded their diet information of macronutrients to reach a goal of 50 grams / day during a two-week intervention period.
Sewall, the course tutor, commented on how much he and the students enjoyed learning what foods are rich in fiber. “We were surprised to find out how high in fiber berries and avocados and exchanged ideas for how to prepare beans and lentils,” she said. “I think this experience will have a lifelong impact. on how we all look at nutrition labels. “
She also noted that the research greatly impressed students in the course. “The students came to the class very happy to talk about what they had eaten and could not wait to analyze the information of the order of midges to make data-based decisions. The effect was interesting. and education at the inspection, “she said. “Our educational research showed that the experience increased students’ interest in science and raised awareness of their dietary habits.”
Graduate student Andrew Oliver, a teaching assistant for the course, coached students through the process and advised them to get plenty of water as well as offer guidance in microbiology and analysis techniques. “Students raised their fiber intake by an average of 25 grams per day, but there was a significant difference in pre-intervention fiber intake,” he said. “A few students had to go from close to zero to 50 grams per day by the end of the study. We all became a little indifferent to the amount of fiber in the food we ate.”
After the intervention, the researchers compared total bacterial composition using DNA sequences and measured the yield of short-chain fatty acids using gas chromatography. In addition to sequencing, the team ran additional tests targeting the well-known fiber degrader, Bifidobacterium.
The researchers found that the two-week intervention significantly altered the gut microbiome composition of an individual, leading to an increase in Bifidobacterium abundance. However, despite the observed changes in gut microbiome shape, they did not find a significant shift in the abundance of these fatty acids.
“We hope to carry out longer dietary fiber interventions and explore how fiber can support the gut mosquito and promote health. At this time during a pandemic, when ‘We need our immune health and healthy vaccine responses, we encourage everyone to think about plant diversity of their diet and add a few beans, berries and avocados where they can,’ ‘Whiteson said.
Source:
University of California, Irvine
Magazine Reference:
Anndra Oliver, Alexander., Et al. (2021) A high-fiber, whole-food diet intervention alters the human gut microbiome but not fecal short-chain fatty acids. mSystems. doi.