Research has shown that there is a positive link between fiber intake and beneficial health results. A few of the reasons why fiber is highly advantageous to the body are slowing the rate of sugar getting absorbed into a person’s bloodstream, helping move the intestines faster while acting as a sort of brush that aids in cleaning the colon, as well as even helping make you more regular, which can help reduce constipation.
As a result, once bacteria metabolizes fiber, it promotes a healthy gut microbiome. According to microbiologysociety.com, a microbiome ‘is the community of micro-organisms living together in a particular habitat. Humans, animals and plants have their own unique microbiomes, but so do soils, oceans and even buildings.’
A recent study has found that when individuals practiced two-weeks of increased fiber in their diets had a substantial change or altering to their gut microbiome as a result. Some of these changes have also increased the species of bacteria within the gut that breaks down fiber.
Yet, what did not increase was the quantity of short-chain fatty acids (SCFAs). SCFAs are produced when bacteria actually breaks down fiber within the microbiome, and are essential to the gut, body, as well as to brain health.
For example, SCFAs are utilized by the colon cells as a source of energy, which aid in cell signaling. Some of them also contain anti-inflammatory properties, which can aid in helping with insulin sensitivity, which has a direct impact on body weight.
The research, which came out in the journal mSystems or American Society for Microbiology, helps pave the way for future studies that hope to further study the association between SCFAs, gut bacteria, and fiber intake.
What Are the Benefits of Fiber?
There are a number of significant benefits to fiber. In fact, a review that was conducted back in 2017 showed how a variety of meta-analyses that found those that consumed the most fiber had a substantially reduced chance of death due to cardiovascular issues or events.
Meanwhile, in the United States, only 1 in every 20 people actually take the daily recommended amount of fiber.
Co-author of the study, Dr. Katrine Whiteson, who also happens to be an associate professor of molecular biology and biochemistry, co-director of the University of California, Irvine (UCI) Microbiome Initiative explains, “The lack of fiber intake in the industrialized world is starving our gut microbes, with important health consequences that may be associated with increases in colorectal cancer, autoimmune diseases, and even decreased vaccine efficacy and response to cancer immunotherapy.”
Since the small intestine is unable to digest fiber, the authors of the study claim that it passes into the colon, which is where the microbes work to break down the fiber. When this happens, SCFs are produced, which many experts claim is vital for a number of factors that affect one’s health.
In order to further understand this, the authors examined the association ‘between a short-term increase in dietary fiber, the makeup of the gut microbiome, and the presence of SCFAs.’
The Two-Week Diet and the Findings
To fully examine this relationship, the research team conducted a study with 26 undergraduate student participants that were enrolled in a biology course at the UCI, and their instructors as well.
During the first week, the participants were asked to follow their normal diet while providing the research team three different stool samples for them to analyze.
On the second week, the participants were made to consume a high fiber diet. Here, they were requested to track their nutritional intake using a fitness app. The goal was to consume at least 40 grams of fiber every single day. In order to help the participants out, the research group gave them 10 meals each week that had a variety of different plants that were high in fiber.
During week three, the research group encouraged the study participants to increase their fiber intake by another 10 grams, making it 50 grams of fiber per day. In that week, the participants were asked to provide another three stool samples for the research group to study.
Graduate student Andrew Oliver, who was also a teaching assistant for the course, said “students raised their fiber intake by an average of 25 g per day, but the variability of pre-intervention fiber intake was substantial.”
He added, “A few students had to go from nearly zero to 50 g daily by the end of the study. We all became a little obsessed with how much fiber was in the food we were eating.”
In order to identify the makeup of the bacteria, the research team studied the samples of the participants using DNA sequencing. They also used gas chromatography in order to measure the SCFAs.
The Change of Microbiome Composition
What the researchers found was that the composition of the participants’ gut microbiomes actually changed ‘by around 8% following the dietary intervention.’ They explained that this was mostly due to the increases of bacteria that is known to breakdown fiber, such as Bifidobacterium, Bacteroides, and Prevotella.
Yet, the research group also shared that they hadn’t seen a ‘statistically significant increase in SCFAs.’ They believe that it was probably because the stool samples that participants provided were not able to represent the precise levels of SCFAs within the gut, which are fundamentally found in the cell walls of the intestines.
The research group also cites that there was a chance that the two-week dietary intervention might not have been long enough to actually see a true change in the SCFAs.
Dr. Whiteson went on to say “we hope to carry out longer dietary fiber interventions and study how fiber can support the gut microbiome 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 the plant diversity of their diets and add some beans, berries, and avocados where they can.”
Recommended For You
