Image from www.mdanderson.org

Probiotics have increased in popularity in the past few years. According to a survey by the National Center for Complementary and Integrative Health, about 4 million US adults (1.6% of the population) used a probiotic or prebiotic supplement in the past 30 days¹. From grocery store aisles devoted to probiotics to social media influencers, there are claims for probiotics, including improvement of everything from constipation to obesity to depression. What is the evidence that probiotics promote health?

Probiotics are gut microorganisms that are helpful in digesting food, producing vitamins, and fighting harmful pathogens. Probiotics are found in naturally fermented foods like yogurt, cheese, and kombucha.  The products we are addressing consist of similar bacteria, commercially manufactured and distributed. 

There is experimental evidence that probiotics can alleviate symptoms of Inflammatory Bowel Syndrome (IBS).  People taking a probiotic with the bacteria Bifidobacterium bifidum MIMBb75 experienced less discomfort, bloating, urgency, and digestive disorder compared to those who took a placebo².

The evidence that probiotic use is helpful for restoring healthy gut flora after a course of antibiotics includes genetic sequencing of stool samples demonstrating increased diversity of gut bacteria and fewer antibiotic-resistant bacteria³.

There is some evidence of a connection between the gut microbiome and the brain. In one study, people with IBS taking the probiotic Bifidobacterium longum NCC3001 had fewer symptoms of depression relative to people taking a placebo⁴.  They also had reduced brain activity on fMRI in response to negative stimuli. More experimental evidence is needed to confirm these relationships. 

There are case reports of sepsis or fungemia from bacteria⁵ or yeast⁶ in probiotics in people with immune system deficiencies. However, the potential for harm is low, and no serious adverse events were reported in clinical trials. The most common side effect for the average healthy person is temporary bloating and constipation, which typically subsides after a few weeks of use⁷.

Think twice before consuming a probiotic pill. A healthy diet including natural sources of gut flora is probably just as good as any pill or drink. We need more experimental evidence before we can be certain of the relative potential benefits and harms of probiotics, natural or in pill form, for various illnesses.  

1. https://www.nccih.nih.gov/research/13-year-trends-for-complementary-approaches-where-questions-are-very-similar-across-years
2. https://pubmed.ncbi.nlm.nih.gov/21418261/
3. https://pubmed.ncbi.nlm.nih.gov/26395781/
4. https://www.gastrojournal.org/article/S0016-5085(17)35557-9/fulltext
5. https://www.clinicalmicrobiologyandinfection.com/article/S1198-743X(14)61883-8/fulltext
6. https://www.sciencedirect.com/science/article/pii/S2211753917300441?via%3Dihub
7. https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/whats-the-deal-with-probiotics#:~:text=There%20is%20no%20clear%20evidence,the%20results%20of%20different%20studies

Image from www.thesportreview.com

Pre-workout supplements are advertised to increase energy and improve exercise performance. TikTok trends claim that “dry scooping”–taking supplements without water–helps the body absorb them faster. What is the evidence for or against such claims?

Because these supplements are not regulated by the FDA, it’s difficult to be certain exactly what they contain. Pre-workout supplements typically consist of protein building blocks (creatine and beta-alanine), vitamins, nutrients, and a notable dose of caffeine. Creatine is theorized to increase focus and beta-alanine to an energy boost. Caffeine can increase heart rate and blood flow. On the basis of a few low-quality studies, claims are made that these three main ingredients slightly enhance performance in extreme athletes but may not significantly impact individuals who exercise moderately (Ghose, 2015; Spillane, Schwarz, & Willoughby, 2014; Duncan et al., 2012).

Dry scooping is associated with a risk of inhaling the powder, with a potential for inflammation or infection. There may also be a risk for overconsumption of caffeine.

Used as directed, some of these supplements have as much caffeine as three cups of coffee. This high amount of caffeine, combined with a person’s daily coffee and soda consumption, can lead to nausea and shakiness. There may also be a small risk of heart rhythm problems.

An alternative to consuming pre-workout supplements may be healthy sources of energy such as whole, natural foods. Bananas and other fruits have carbohydrates that break down quickly and give us energy. Coffee is a familiar, safe, and readily available source of a caffeine energy boost. It’s healthy to develop good habits of diet and activity in all aspects of life, not just at the time of a workout.

It’s not clear whether consuming pre-workout supplements has more potential for benefit than for harm. If it holds some appeal for you, ensure the supplements have familiar ingredients and be cautious about your daily caffeine intake. 

https://www.livescience.com/53095-do-preworkout-supplements-work.html

https://blog.nasm.org/pre-workout-guide

https://health.clevelandclinic.org/dry-scooping-tiktok-trend/

https://health.clevelandclinic.org/does-taking-a-pre-workout-actually-work/