Our Gut Bugs Make Tiny Metabolites That Have Gigantic Jobs

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Cultivating Our Gut Microbiome to Stifle Disease (Part 5)

In this series, we’ll share how the latest developments on this medical frontier are transforming our approaches to illness and offering new strategies to heal and prevent disease.
Previously: Dysbiosis, an imbalance of microbes living inside us, is linked to several diseases but scientists still struggle to define, diagnose, and treat it. 

Based on current science, one of the most important roles of the gut microbiome—the community of bacteria, viruses, and fungi in our gut—is conducting an essential bit of biochemistry that provides us with short-chain fatty acids. These molecules are essential to our health and play several critical roles in the body.

Short-chain fatty acids (SCFA) are anti-inflammatory. That means they cool the fire of inflammation that our body uses to burn off pathogenic invaders. Unfortunately, this inflammation function is widely dysfunctional in modern people, because of constant triggering by stress, environmental toxins, and processed foods.

The result is that instead of burning off infections, inflammation burns the mind and body instead. The resulting damage is linked to nearly every modern disease—mental and physical.

Regulating this immune response is just one of the jobs that SCFAs do for us. They also work to prevent and regulate several diseases, including Type 2 diabetes, heart and liver disease, obesity, cancers, psychiatric disorders, arthritis, neurodegenerative diseases, gut disorders, periodontal disease, and more. To do their jobs effectively, we need to feed them well.

Eating for Trillions—Prebiotics and Probiotics

Our microbes want prebiotics—plant-based fiber. It keeps them healthy and nurtures the kind of community that can produce plenty of SCFAs and ward off invasions of pathogenic microbes. If that community is damaged, for example, from a round of antibiotics, we can also add new microbiota to our gut by eating probiotics. These are foods that contain live beneficial bacteria—fermented foods.

Nurturing these microbes can be the difference between health and disease.

“They are guardians of our health, and we need to be protective of them. Their ecosystem is so sensitive,” Dr. William Li, renowned physician, scientist, and author of “Eat to Beat Your Diet,” told The Epoch Times.

“If we feed our gut bacteria damaging substances like excess sugar or salt, ultra-processed food, chemical synthetic preservatives, artificial colors and flavors, they can be effectively poisoned. Then, the bacteria don’t cooperate and behave as they should, harmful bacteria can grow, and the entire ecosystem is disrupted. Inflammation will rise.”

While eating fermented foods regularly can support the microbiome, it’s likely even more important to sustain the population of microbes already inside you. That’s because before microbes can get to their primary destination, the cecum, they need to pass through the stomach. Our stomach uses enzymes and hydrochloric acid to break down food. Few bacteria can survive here, which can limit the effect of ingesting probiotics.

When food leaves the stomach, it arrives at the main place it gets used—the small intestine. This is where the small intestine, pancreas, and gallbladder help 90 percent of food cross into the bloodstream, giving us the nutrients that fuel us.

Some bacteria live in the small intestine, but the vast majority of our gut microbes (fungi and bacteria) live in our cecum—the first part of our large intestine. Here, microbes feed on the small intestine’s leftovers and carry out their essential work.

“When we feed them, they pay us back by giving us these anti-inflammatory substances,” Li said. “[The microbiome] relies on dietary fiber. It digests that and produces metabolites. These metabolites have remarkable health benefits.”

Short-Chain Fatty Acids

Bacteria metabolize plant fiber through fermentation and create metabolites. Metabolites are typically small molecules and exist in tremendous variety. They get their name from the fact that they result from metabolism and contribute to metabolism. Metabolism is the biochemical process of turning the food we eat and the air we breathe into our molecular body and all its various activities.

Our gut microbes create three main metabolites (that we know of), the short-chain fatty acids known as acetate, butyrate, and propionate.

This trio indirectly reduces appetite, limits food intake, and regulates blood glucose. Acetate, the most abundant short-chain fatty acid, nurtures the growth of other beneficial bacteria and plays vital roles in cellular metabolism, including supporting insulin sensitivity and body weight control.

Type 2 diabetes is associated with insulin resistance or sensitivity, a process of insulin being unable to clear glucose from the blood, which can lead to a dangerous buildup.

“Good bacteria lowers our sensitivity to insulin,” Li said. “When insulin goes up, it’s useful for energy, but if it continues to because your body is sensitive and not absorbing it, it is a road to diabetes.”

Our hunger and digestion go awry when we don’t have the microbes we need to produce sufficient SCFAs. Not surprisingly, obesity is associated with a low level of short-chain fatty acids, which are considered a biomarker of a healthy microbiome, according to Leigh A. Frame, associate director of the George Washington University Resiliency & Well-Being Center and a nutrition and microbiome expert.

Other issues we might not connect to diet and digestion are also linked to short-chain fatty acids. These metabolites have been found to regulate immunity, as well as being protective against diabetes, cancer, cardiovascular disease, kidney disorders, and neurodegenerative conditions.

They may even play a role in the development of an infant’s immune system. In a study published in Nature Communications in 2015, short-chain fatty acids were measured in pregnant women and then compared to the number of infant doctor visits for coughing and wheezing in the first year of life.

“Strikingly higher levels of serum acetate, but not propionate or butyrate, were significantly associated with fewer respiratory problems in the infants,” according to the study.

Generally, where short-chain fatty acid production is low, diseases flourish. A 2021 article in Trends in Microbiology explains that short-chain fatty acids influence health in three ways:

  1. They alter levels of histone acetyltransferase and histone deacetylases, which work to protect our DNA by activating gene expression, DNA replication, and DNA repair.
  2. They signal specific fatty acid-sensing G-protein-coupled receptors, which are expressed on immune cells and on epithelium and endocrine cells. They are central to metabolism and also help regulate an incredible range of bodily functions, including sensation, growth, and hormone responses.
  3. They give the body anti-inflammatory mechanisms in the periphery and tissues due to the first two mechanisms.

Eat More Fiber

The single most important way to ensure your gut is making adequate short-chain fatty acids is to eat sufficient fiber.

The Western diet is problematic because it’s high in saturated fat and sugar and low in fiber. Most people worldwide consume less than 20 grams of dietary fiber per day, according to a 2019 review in The Lancet. The article said 25 to 29 grams of fiber daily is adequate, while more than 30 grams per day confer additional benefits.

Fiber also speeds up food transit time in the colon and decreases pH, a measurement of acidity versus alkalinity. A lower pH is ideal in the gut because it’s associated with inhibiting pathogen growth and increasing short-chain fatty acid production.

“When we add fiber to the diet, it’s a positive feedback loop,” Frame told attendees at the recent Malibu Microbiome Meeting. “But we should be quite cautious. You should have a slow, gradual transition to a high-fiber diet.”

While health findings associated with microbiota and metabolites have been tremendous in the past two decades, Li said it’s humbling to consider how much is still undiscovered.

“In truth, we don’t know that much,” he said. “There are certainly many mechanisms, many pathways we have yet to discover in research.”

Profile of a Top Bug

Faecalibacterium prausnitzii bacteria make up 5 to 15 percent of most people’s total microbiome. It’s the main producer of butyrate, a critically important short-chain fatty acid that helps regulate the immune system with strong anti-inflammatory compounds.

Butyrate fuels intestinal cells. It reduces gastrointestinal inflammation, stabilizes intestinal permeability, supports healthy mucus production for the gut lining, and improves colon motility. Additionally, it plays a role in mood regulation and insulin sensitivity, as well as having anti-cancer effects.

Declines in F. prausnitzii numbers have been associated with autoimmune diseases such as celiac disease, Crohn’s disease, ulcerative colitis, and psoriasis, as well as in chronic illnesses such as Type 2 diabetes, colon cancer, and irritable bowel syndrome.

Dr. Akil Palanisamy describes this keystone bacteria in his book “The T.I.G.E.R. Protocol: An Integrative 5-Step Program to Treat and Heal Your Autoimmunity.”

Palanisamy notes that, unfortunately, there are currently no probiotics that contain F. prausnitzii, although levels can be raised by eating a diet of diverse prebiotic foods such as leafy green vegetables, mushrooms, apples, and those that include polyphenols, inulin, resistant starches, and arabinogalactan (found in carrots, radishes, pears, tomatoes, and coconuts).

Information adapted from The T.I.G.E.R. Protocol by Akil Palanisamy, M.D. Copyright 2023 by Akil Palanisamy, M.D. With permission from Balance, an imprint of Grand Central Publishing. All rights reserved.

Short-Chain Fatty Acids and the Brain

The clear link between microbiota deficits and neurological conditions reveals the interdependence of the gut and brain. Short-chain fatty acids could play a key part in gut-brain signaling related to neurodevelopmental disorders as well as neurodegenerative diseases, according to a 2020 article in Frontiers in Endocrinology. 

Among the evidence pointed out in the study:

  • Fecal short-chain fatty acid concentrations are lower in patients with depression. Butyrate in particular is noted for its antidepressant-like effect.
  • Children with autism spectrum disorders have had both lower and higher levels of certain short-chain fatty acids than control groups.
  • Recent studies have also suggested that an intestinal bacteria imbalance plays a role in the development of anxiety, bipolar disorder, psychosis, Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis.

Next:  New studies are illustrating just how powerful the gut microbiome can be in helping our bodies heal from cancer, heart disease, and more.

Read Part 1 – Killing Bacteria with Antimicrobials and Antibiotics May Be Shortsighted, According to New Science About the Microbiome

Read Part 2 – How the Gut Cures and Creates Disease

Read Part 3 – Why Scientists Are Obsessing Over the Bugs in Our Stool

Read Part 4 – Decoding Dysbiosis: Are Your Gut Microbes Out of Whack?

Important Notice: This article was also published at www.theepochtimes.com by Amy Denney where all credits are due.


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