Gut Bacteria and Obesity, digestion and the microbiome – Feature Article
Gut Bacteria and Obesity is there a link? To answer this question we need to look at the microbiome and the science behind it. The UK is becoming more and more overweight. As of late 2017, 29% of the adult population were classified as obese and 64% were overweight or obese (NHS Digital, 2019). This figure is creeping up every year and is nearly prevalent in children and young adults with more than 20% of year 6 ages school children being obese (Health survey for England, 2017)
It is somewhat reductionist of us to think that just eating more and moving less will lead to weight gain; which is true if you prescribe to the laws of thermodynamics. However, what often isn’t considered is if there is anything else about our diet and lifestyle that causes weight gain, other than just calories in Vs calories out. Rather than just storing unused calories as fat, is there another interaction with our body that causes us to pile on the weight? Does what we eat impacting us in ways we can’t see? Well allow me to introduce you to the gut microbiome.
So what is the microbiome?
The gut microbiome is a massive biological network of bacteria, fungi and other micro-organisms, all living harmoniously in your digestive tract. It ensures our food is properly broken down, nutrients absorbed and essentially keeps us in good health. This ecosystem is so massive and so diverse that we could almost be considered to be a supra-organism, such is the reliance on this colony. We simply need it in our gut to ensure healthy digestion and nutrient metabolism. The microbiome is influenced by factors from birth and the more diverse your gut flora is, the more health benefits you will receive. A good, varied diet with plenty of good quality sleep, high levels of exercise and low levels of stress all go toward a healthy regulation.
Is there a role for the microbiome in weight regulation as well as nutrient absorption? The two do of course go hand in hand. If the volume of calories we consume is the chief reason for how much weight we may put on or lose, can the so-called ‘good’ bacteria in our gut aid or hinder these processes?
Does a good microbiome prevent obesity?
Well, there are plenty of animal studies that certainly suggest that a certain ‘healthy’ microbiome is associated with lower adiposity whereas straying from this has shown links with higher levels of fat storage and certain metabolic disorders (Bauer et al., 2016). We must keep in mind correlation does not necessarily mean causation however there is a growing body of evidence with the same findings and with such studies now finding the same results in humans (Palleja et. Al 2016), it is hard to ignore.
How does this happen?
Your body likes to stay in a state of homeostasis but unfortunately the Universe is plagued by agents of disruption that like to alter this and unfortunately, your gut can succumb. Almost everything is controlled by hormones, working within a feedback loop with your brain and it is thought that an abnormal microbiome can wreak havoc with this system. Enter the gut-brain axis. Levels of leptin and insulin (amongst other chemical messengers) can become compromised and we may lose the signal that tells us to stop eating.
Is that it?
No. There are a multitude of theories and hypotheses as to why a poor or unvaried microbiome may encourage obesity. Certain metabolic processes influenced by gut flora has also been shown to alter levels of thermogenesis-a key player in the utilisation of energy expenditure (Parseus et. Al., 2017). So imagine not only can you not stop eating because your brain isn’t telling you that you are full, your body is also now no longer efficiently burning the fuel you are storing. All because of a few trillion tiny microbes not being kept in line. Bariatric surgery has also been seen to impact the microbiome due to the invasive nature of the techniques and those who are undergoing or have recently experienced such procedures may wish to be mindful of this fact.
How do I increase the variety of my microbiome?
With tackling the pandemic of obesity continuously being at the forefront of Western medicine, new and innovative ways (as well as some traditional remedies) are being shared on how to improve the state of our colon community. Probiotic drinks, natural yogurt and food such as sauerkraut and kimchi are bursting with a variety of cultures that can restore order quite quickly. Lactobacillus and Bifidobacterium are probably the most well-known of these good bacteria and are found in abundance. Good quality sleep, not shying away from the dirt and lots of fresh, outdoor living will also improve the quality of your gut phylum. Alternatively, you can try faecal transplantation if you wish and at your own risk.
What do we conclude?
The findings of the investigation undertaken here highlight that the microbiome plays in important role in weight management. This occurs via a number of biological and chemical channels and further reading will demonstrate that it isn’t just your BMI that can be hit. Your overall health relies on a diverse, well maintained gut and you can expect to hear more about this in the future as the research becomes more main stream. I hope that answers the question about “Gut Bacteria and Obesity”
References for Gut Bacteria and Obesity is there a link?
O’Keefe, S., Li, J., Lahti, L., Ou, J.C., F. & Et al. (2005) ‘Fat, fibre and cancer risk in African Americans and rural Africans’, Nature Communications, 6 pp.28/10/2018 Available at: https://doi.org/10.1371/journal.pone.0039361 .
NHS Digital. 2019. Statistics on Obesity, Physical Activity and Diet, England, 2019. [ONLINE] Available at: https://digital.nhs.uk/data-and-information/publications/statistical/statistics-on-obesity-physical-activity-and-diet/statistics-on-obesity-physical-activity-and-diet-england-2019. [Accessed 12 November 2019].
Palleja, A., Kashani, A., Allin, K. H., Nielsen, T., Zhang, C., Li, Y., … Arumugam, M. (2016). Roux-en-Y gastric bypass surgery of morbidly obese patients induces swift and persistent changes of the individual gut microbiota. Genome medicine, 8(1), 67. doi:10.1186/s13073-016-0312-1
Parséus, A., Sommer, N., Sommer, F., Caesar, R., Molinaro, A., Ståhlman, M., … Bäckhed, F. (2017). Microbiota-induced obesity requires farnesoid X receptor. Gut, 66(3), 429–437. doi:10.1136/gutjnl-2015-310283