Does exercise improve our gut microbiome, and what does it mean for menopause?
Our gut microbiome is made up of trillions of microorganisms, including bacteria, viruses and fungi. The majority of our gut bacteria live in the large intestine, and a person’s gut microbiome will be as individual to them as their fingerprint. There is a huge amount of variability and diversity of bacteria which is impacted by both internal and external factors. The stability of our microbiome relies on the balance between the internal and external factors that influence it. Our microbiome plays a role in our health on many levels and can be positively or negatively affected by illnesses, antibiotics, diet, stress, sleep and hormonal changes that occur across our lifespan, including menopause. Recent studies have shown the benefits of exercise and the gut microbiome in overall health, immunity, mood and digestion.
The gut microbiome at a glance
Believe it or not, we are 90% microbes and only 10% of self, so the functioning of our gut microbiome and its influence on our health is definitely up there on the list of priorities. The gut microbiome plays a role in the functioning of our metabolism, immune system and our hormones. In particular, there are two dominating types of bacteria that make up our gut microbiome, called Firmicutes and Bacteroidetes. They make up the majority of the gut microbiome, and it’s when the balance of these becomes disrupted, that we can experience changes in our health.
Many studies have shown that women in post menopause have higher amounts of Firmicutes and lower amounts of Bacteroidetes, compared to premenopausal women. This is also seen in obesity and type 2 diabetes. Weight gain and redistribution of fat to the abdomen is a common occurrence in the menopause years as is the risk of metabolic disorders including obesity and type 2 diabetes. This would indicate that there may be a connection.
Firmicutes and Bacteroidetes are classes of bacteria that contain many different types of species within each class. The most well known Firmicute is Lactobacillus, and Bacteroidetes is Bifidobacterium. These types of bacteria are beneficial for gut health, breaking down dietary fibre and resistant starch by fermentation and producing short chain fatty acids such as butyrate. Many health benefits occur, including reducing inflammation, protecting the gut lining, production of antioxidants and hormones for metabolism.
Many factors play a role in establishing a healthy gut microbiome including a diet that is predominantly plant based, high in fibre, complex carbohydrates and fermented foods such as dairy, stress reduction and getting good quality sleep. There is also growing evidence that exercise, independent of diet, sleep and stress can change the composition of the gut microbiome.
The impact of exercise on the gut microbiome
Exercise has many health benefits including heart, brain and bone health, increasing muscle mass and decreasing fat which optimises metabolism, it is a mood enhancer and will decrease stress and improve sleep. When our gut microbiome is at its best, it also has many health benefits including improved digestion, regulating our immune system, protecting against certain diseases and boosting mood. This is when the ratio of Firmicutes and Bacteroidetes is balanced – everything is in harmony.
So what happens when menopause disrupts the gut microbiome balance and what effect can exercise have to rebalance it?
Although there hasn’t been a lot of research looking at menopause and exercise on gut health together, there have been some studies that have compared groups of pre menopausal women. One study that included 40 women aged 18-40 was grouped as either active or sedentary. The active group participated in 10 hours of exercise over 7 days, and the sedentary group participated in less than 30 minute sessions of moderate exercise, 3 times a week. The active group was found to have a higher abundance of gut bacteria, with 11 different types identified compared to the sedentary group. It is important to note in this study, that the active group ate more dietary fibre than the sedentary group, which is known to be beneficial to the gut microbiome. Other studies have shown that moderate exercise can increase the types and numbers of gut bacteria that are beneficial for our health, in particular the Firmicutes.
In regards to menopause, it is known that the Firmicutes increase and Bacteroidetes decrease when blood oestrogen levels are low, which has an impact on weight gain and risk of type 2 diabetes and other conditions. As oestrogen declines in menopause, redistribution of fat to the waist also occurs, which further impacts weight and the risk of metabolic diseases. The relationship between menopause and the impact of exercise to balance the Firmicutes and Bacteroidetes is not known and more research is needed to fully understand the mechanisms involved.
Watch this space as new research is published and we learn more about the relationship between menopause, exercise and the gut microbiome. It may be the key to understanding weight gain and decreasing disease risk.
References:
1 Atlas Biomed, How Does Exercise Affect The Gut Microbiome?
https://atlasbiomed.com/blog/how-does-exercise-affect-gut-microbiome/
2 Atlas Biomed, What are Firmicutes Bacteria and Why Are They Important?
https://atlasbiomed.com/blog/guide-to-firmicutes/
3 Bressa C et al, Difference in gut microbiota profile between women with active lifestyle and sedentary women, PLoS One, 2017 Feb 10;12(2)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5302835/pdf/pone.0171352.pdf
4 Everyday Health, Can Exercise Boost My Gut Health?
https://www.everydayhealth.com/fitness/can-exercise-boost-my-gut-health/
5 Monda V et al, Exercise Modifies the Gut Microbiota with Positive Health Effects, Oxid Med Cell Longev, 2017 Mar 5 Article ID 3831972
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5357536/
6 Peters BA et al, Spotlight on the Gut Microbiome in Menopause: Current Insights, Int J Women’s Health, 2022;14:1059-1072
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9379122/
7 The Conversation, Gut health: does exercise change your microbiome?
https://theconversation.com/gut-health-does-exercise-change-your-microbiome-140003
8 Zhao H et al, Compositional and functional features of the female premenopausal and postmenopausal gut microbiota, FEBS Letters, 593 (2019) 2655-2664
https://febs.onlinelibrary.wiley.com/doi/epdf/10.1002/1873-3468.13527
