Probiotics are live microorganisms that are taken to improve or maintain the health of our gut microbiome (the microbes associated with the digestive tract). There are many types you can purchase, which contain a variety of different microorganisms, in different amounts.
A common recommendation is that individuals take probiotics during or after being on antibiotics because antibiotics can clear out good bacteria along with the bad. Probiotics may also be recommended for those who have gastrointestinal disorders like colitis, IBS or IBD, as these are diseases that cause damage to the intestinal lining of the gut. There are a number of other infections where probiotic usage can be indicated and there are even claims that probiotics can aid in weight loss, which is still being researched. You may have seen over the counter products that are labelled “Probiotics + Weight Loss”. However, probiotics are still not a clinical recommendation given the lack of consistent, robust results within research and that the specific microbes that may be associated with weight or obesity have yet to be determined. What is clear, is that a diet low in fibre and high in fat, preservatives, and refined carbohydrates can harm the gut microbiome. Studies have shown that probiotic use along with diet and physical activity result in greater benefit than probiotics alone.
You know how every snowflake is unique? This kind of applies to our gut as well. There are trillions of different microbes that live in our gut, and the composition of these microbes are different for each person. This environment is also constantly changing, especially for those with GI disorders who may experience flare-ups. A flare may mean inflammation, diarrhea, frequent bowel movement, pain and nausea. Some probiotics may work better than others, some not at all. Researchers are still trying to figure out which probiotics work best, how long they should be taken and whether the probiotics are actually able to integrate themselves into the host environment (aka your gut). It’s also helpful to remember that your gut does not function independently, and includes the pancreas, liver and gallbladder which produce hormones and enzymes necessary for digestion and metabolism.
Probiotics available as dietary supplements (not the ones found in food) are regulated by the FDA. However it is recommended to take “third-party” tested probiotic products, which will be indicated on the label. Research has found that a dosage of 5 billion or greater per day is the most effective in comparison to lower dosages.
Many people do have success with probiotics! And overall they aren’t unsafe. Systematic reviews of research have found no adverse effects with children, adults or older adults. Those who are immune compromised are advised to be cautious. A downside is they can be quite pricey. If you have been taking them for 4 weeks and haven’t noticed a change, it’s unlikely you will gain any benefit. If you notice allergic reactions or intolerance, also stop taking them. This could include pain, gas, and diarrhea. There is no definitive length of time to continue using probiotics, some individuals notice a positive change after a few weeks, stop taking them and have lasting effects. While others may return back to their pre-probiotic state. Including probiotic rich foods into your diet such as yoghurt and fermented foods, to continue to support the healthy environment is something to consider. However, the long-term goal is to create and maintain a healthy, diverse environment of microorganisms and a key way to do that is with a diverse, nutritious diet including fruits and vegetables.
https://www.nccih.nih.gov/health/probiotics-what-you-need-to-know
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4566439
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7465252/