First study examines the impact of exercise on the microbiome in people with cancer

Building on their previous August and October In 2022 studies, the research team sought to examine associations between physical activity, BMI, and gut microbiome diversity in people with colorectal cancer.

The team collected data from 179 people registered with the ColoCare Study between October 2010 and March 2018. The ColoCare study is an international cohort of people recently diagnosed with stage I-IV colorectal cancer.

Data collected included preoperative stool specimens and BMI measurements from medical records. The scientists then performed 16S rRNA gene sequencing on the stool samples to determine the diversity of the participant’s microbiome.

Additionally, the scientists used the BMI measurements to categorize the participants into three groups:

• Healthy weight: BMI ≥18.5 and
• Overweight: BMI ≥25 and
• Obese: BMI ≥30 kg/m2

Participants also completed an adapted version of the International Physical Activity Questionnaire (IPAQ) to determine their level of physical activity during the year prior to their diagnosis of colorectal cancer. The scientists calculated the duration and hours of physical activity per week in hours of equivalent metabolic tasks per week (MET hrs/wk).

Using these calculations, the researchers classified participants as inactive if their physical activity was less than 8.75 MET hours per week and active if their activity was 8.75 MET hours per week or more.

The scientists noted that having a MET of at least 8.75 meets the US Department of Health and Human Services guidelines recommending at least 150 minutes (2.5 hours) per week of moderate activity. This directive may also apply to cancer survivors.

Next, the research team grouped the participants into four physical activity level/BMI categories:

• Healthy/active weight: 26 participants
• Healthy/inactive weight: 33 participants
• Overweight/obese/active: 46 participants
• Overweight/obese/inactive: 74 participants

After compiling the data, the scientist found:

• The gut microbiome of active, healthy-weight participants was more diverse than that of inactive participants.
• Obese participants had lower alpha diversity than those classified as having a healthy weight.
• The gut microbiome of healthy/active weight participants was more diverse than those classified as overweight/obese/inactive.
• Faecalibacterium-a beneficial bacterium-was enriched in active participants regardless of BMI.
• Overall, lower gut microbial diversity was observed in inactive, obese, and overweight/obese/inactive participants.

Additionally, gut biome diversity was not statistically significantly associated with participant stage at diagnosis, tumor site, and neoadjuvant treatments. Additionally, the researchers found no differences in individual or combined physical activity and BMI groups for people with rectal cancer.

The research team suggests that this evidence supports an association between higher physical activity levels and greater gut microbiome diversity and abundance in people with colorectal cancer, even those with obesity.

While these results show an association between moderate exercise and increased gut biome diversity, limitations of the study include:

• The study was cross-sectional and did not follow people. Therefore, he cannot establish cause and effect.
• All patients had bowel cancer, and there was no healthy comparison group.
• The rRNA gene sequencing used in the study may be inaccurate in some respects.
• This study used participants diagnosed with colorectal cancer. Therefore, it is not clear whether the results would be the same in people without cancer.
• Physical activity was self-reported, which may result in misclassification of active versus inactive participants.

Dr. Gabriela Rodriguez Ruiza bariatric surgeon certified by the VIDA Wellness and Beauty Board of Directors, said Medical News Today:

“The gut biome contains a community of billions of bacterial cells that produce compounds called short-chain fatty acids (SCFAs) during the fermentation process. These SCFAs act as signaling molecules that tell the cells of your intestinal lining do not release pro-inflammatory cytokineswhich are associated with the development of autoimmune diseases such as rheumatoid arthritis and inflammatory bowel disease.”

Dr. Rodríguez Ruiz explained that disruption of the gut microbiota – also known as gut dysbiosis – can be an important factor in the development of inflammatory diseases.

Dr Bill Rawlsauthor of The cellular wellness solution and Unlock Lyme and co-founder and medical director of Vital dietexplained gut dysbiosis in more detail at DTM:

“Dysbiosis occurs when the balance of bacteria in the gut changes from [healthy] flora to potentially pathogenic bacteria. […]. Whether [healthy] flora are suppressed, pathogens can damage the intestinal lining, causing digestive dysfunction, but also secrete substances that affect brain function and cellular health throughout the body.

Dr. Rawls said poor diet and chronic stress are major contributors to gut dysbiosis. A high consumption of foods high in carbohydrates and animal fats are also factors.

Another common factor [for gut dybiosis] is the excessive and prolonged use of antibiotics. Antibiotics suppress [healthy] flora and allow pathogens to thrive.
— Dr. Bill Rawls

“In conventional medicine, we treat chronic inflammation by artificially blocking inflammatory processes. Although this may reduce damage associated with the inflammatory process, it does not address the underlying causes of cellular stress,” Dr. Rawls explained.

“If factors causing cellular stress are not addressed, healing is impaired and chronic disease progresses,” he noted.

“The first step is to make dietary changes to include more probiotic-rich foods in your diet, such as fermented vegetables like kimchi or sauerkraut, kefir, yogurt, and other cultured dairy products.”
— Dr. Gabriela Rodriguez Ruiz

Dr. Rodríguez Ruiz suggested that probiotics in supplement form could also help.

“In addition, a diet rich in fruits and vegetables is important for supporting the diversity and health of your microbiome, as these foods contain vitamins and minerals essential for good gut health,” she said. DTM.

“Other lifestyle practices, such as getting enough sleep and reducing stress, can also help improve the diversity and health of your gut biome. Regular exercise can also help maintain a healthy gut by reducing the inflammation and improving gut motility,” she added.

Moreover, he suggested eat less meat to increase the diversity of bacteria in the gut. Although meat, especially fish and poultry, are important sources of protein, Dr. Rawls thinks people generally don’t need to eat large amounts of them.

Overall, to help promote a healthy gut biome, Dr. Rawls advised, “eat the right foods, minimize stress, and stay physically active.”