There are billions of bacteria living in in our guts. The role that gut bacteria play in immune health has been recognised for some time but more recent research has highlighted the influence our gut bacteria may have on our weight.

To support our gut health we need a good balance of beneficial bacteria in our guts versus the less beneficial or pathogenic types. When this balance becomes altered in favour of the latter types our health can suffer and our body fat can increase.

Recent research has observed how altered bacteria resulting from taking antibiotics can lead to a change in cell signalling within the body. These changes resulted in the subjects putting on weight.

One change noted by researchers studying the effects of antibiotics taken to eradicate Helicobacter Pylori was that there wasn’t a fall in a hormone called ghrelin after a meal. Ghrelin, signals to our brain that we are hungry, it usually falls after a meal to prevent us from overeating.

Increased levels of leptin were also evident. Leptin is a chemical messenger that helps to control appetite by sending signals to the brain to say we are full. If levels of leptin are increased this can lead to leptin resistance, which means our brain doesn’t receive the message to stop eating.

Antibiotic use leads to an altered gut flora. They destroy the good bacteria in the gut as well as the less beneficial bacteria. Other negative influences include prolonged stress, chlorinated water, steroids and a diet high in refined carbohydrates or sugar.

Eating a wholefood diet and avoiding sugar will help to maintain a healthy gut flora. Fermented foods contribute to a healthy flora and can be a regular part of our diets. Try including sauerkraut, other fermented vegetables, kefir or fermented soy. To re-establish a healthy bacterial population in your gut after antibiotic use a good quality probiotic supplement is usually required.

Sarah Hanratty BSc N.Med

Francois, F., Roper, J., Joseph, N., Pei, Z., Chhada, A., Shak, J. R., de Perez, A. Z. O., et al. (2011). The effect of H. pylori eradication on meal-associated changes in plasma ghrelin and leptin. BMC gastroenterology, 11(1), 37. BioMed Central Ltd. doi:10.1186/1471-230X-11-37

Harris, K., Kassis, A., Major, G., & Chou, C. J. (2012). Is the gut microbiota a new factor contributing to obesity and its metabolic disorders? Journal of obesity, 2012(Figure 1), 879151. doi:10.1155/2012/879151