More and more people are prioritizing their gut health.
Whether it’s to relieve uncomfortable bloating or gas, promote regularity, or simply build a healthy gut microbiome, it’s increasingly recognized that the foods we eat affect our digestive health and, in turn, our overall health.
It’s no surprise that supplements that claim to boost gut health are making the rounds on social media and online.
Are Gut Health Supplements the Key to Better Digestive Health? Here’s what you need to know.
What does “gut health” really mean?
Gut health is a popular but poorly understood term. It is widely accepted by bloggers and social media influencers, but has no agreed upon scientific definition.
Many experts define gut health by the absence of gastrointestinal symptoms (eg, bloating, gas, abdominal pain, diarrhea, constipation) and disease (eg, inflammatory bowel disease, colon cancer).
Gut health can also refer to having a greater diversity of microbial species in your gut microbiome, the community of trillions of bacteria and other microorganisms that live in your colon.
A diverse microbiome can help ward off disease-causing bacteria and viruses. And it’s thought to protect against asthma, inflammatory bowel disease, depression, obesity, type 2 diabetes and heart disease, among other conditions.
Your gut microbiome also interacts with your immune system and thus helps regulate inflammation in the body.
Do gut supplements live up to their hype?
While some supplements have solid evidence to support their gut health claims, others do not.
L-glutamine supplements, for example, are promoted to “heal the gut lining,” “strengthen the gut wall,” and treat “leaky gut” despite limited evidence. (Leaky gut, or intestinal permeability, occurs when the lining of the gut becomes more permeable than normal, allowing toxins to pass into the bloodstream.)
Glutamine, an amino acid produced by skeletal muscle and supplied through diet, nourishes the cells that line the intestinal tract, thereby helping to build a strong intestinal barrier.
Only two small studies support a possible role for glutamine in IBS. Among 44 patients, daily glutamine supplementation (15 g) for six weeks combined with a low-FODMAP diet improved IBS symptom severity scores to a greater extent than diet alone. (The low-FODMAP diet alone has also been shown to be helpful.)
Preliminary research also suggests that taking glutamine (15 g daily) helps relieve symptoms of post-infectious, diarrhea-predominant IBS. Larger studies are needed to confirm these findings.
A 2021 review of seven clinical trials concluded that glutamine supplements did not improve symptoms of Crohn’s disease, an inflammatory bowel disease.
Collagen, the protein that forms the connective tissue in skin, bones, muscles, tendons and ligaments, has been called a “digestive superfood.”
Collagen supplements are touted to strengthen the lining of the gut, improve gut permeability, aid digestion, and relieve IBS symptoms. Bone broth, a source of collagen, is also promoted for gut health.
I found only one published study that was conducted in humans. Among 14 healthy women who took 20 g of collagen peptides for six weeks, most reported fewer mild digestive symptoms, including bloating. There was no control group for comparison. Hardly a rigorous study.
Probiotic supplements, on the other hand, have been the focus of much research.
Randomized controlled trials have shown that specific strains of probiotic bacteria can improve ulcerative colitis, constipation, IBS symptoms, antibiotic-associated diarrhea, and traveler’s diarrhea.
However, this does not mean that taking a probiotic supplement a day is a fast track to a healthy gut for people without gastrointestinal disease.
Although studies in healthy people show that taking a probiotic supplement increases the amount of healthy bacteria in the gut, this may or may not be a good thing.
It’s possible that taking a concentrated amount of several probiotic strains can disrupt the balance of your gut microbes. You may not only be pushing out some of the bad germs, but some of the good ones as well.
Probiotic supplements can have different effects on different people depending on their unique gut microbiome.
Research also shows that taking a probiotic supplement after antibiotic treatment slows the return of normal bacteria to the gut.
Small studies show that supplements of prebiotics, fibers that feed good gut microbes, help treat constipation, regulate gut inflammation, and favorably alter the composition of the gut microbiome.
However, it’s best to feed your gut bacteria with fiber-rich whole foods rather than a purified prebiotic supplement. Prebiotic supplements can make bloating and gas worse in some people with IBS.
How to promote a healthy gut
There is no quick fix to a healthy gut or, for that matter, a flat stomach, despite what you see on TikTok.
However, evidence points to healthy lifestyle habits that can benefit gut health. These include regular exercise, adequate sleep, stress management and limiting alcohol intake.
The same goes for healthy eating. Diet is considered the most powerful tool that can change the composition and activity of the gut microbiome.
A diet rich in whole grains, vegetables, fruits, nuts, seeds, beans, and lentils provides prebiotic fiber, polyphenols, and other compounds that nourish healthy gut bacteria. Fermented foods that contain probiotic bacteria are also thought to be beneficial for gut health.
When to consult your doctor
Persistent gastrointestinal symptoms such as diarrhea and abdominal pain may indicate a health problem that requires medical attention.
Consult your doctor before experimenting with supplements.
Leslie Beck, a Toronto-based private practice nutritionist, is the director of food and nutrition at Medcan. Follow her on X @LeslieBeckRD
