Gut Bacteria and Weight Management
If you are a regular reader of this blog, you’ll know we all have a fascinating ecosystem of bacteria living within our digestive system. Collectively called the microbiome, over 2000 different species can potentially make our gut their home.
It was previously believed these bacteria really only made a contribution to our digestive health. Indeed they are crucial to a healthy digestive system, which in turn has a knock–on effect on the health of the rest of the body
Recent research however is revealing the influence of the microbiome reaches far wider than this, because the gut bacteria produce signalling molecules which travel all around the body, affecting diverse body processes.
In this blog we’ll look at how your microbiome can affect your weight.
Your Unique Microbiome
Did you know your microbiome is totally unique? You and I have different species in charge. Our microbiome is donated to us via our mother if we had a natural birth, and over life it’s influenced by diet, stress levels, lifestyle and medical drugs.
Scientists first noticed the microbiome of obese people differed significantly from those of lean people. Overweight people had less variety of bacterial species living in their gut.
What’s more, when people lose weight, their microbiome alters too.
Having a predominance of certain species of bacteria appears to make it easier for us to lose weight. It’s thought these bacteria may produce chemicals which boost our metabolism.
The Microbiome and Carbohydrates
We obtain energy from carbohydrates in our food, but we are unable to digest some types of carbohydrates which are better known as fibre. Our gut bacteria, however, can liberate energy from fibre, and people who have species of bacteria which are better able to do this have been found to have more difficulty losing weight.
This is believed to be because the bacteria produce energy from the carbs, effectively meaning more energy is harvested from food than it would otherwise be. So if you and I eat exactly the same meal, I may be obtaining more energy from it courtesy of my gut bacteria, so I will tend to gain weight more readily.
Bacteria and Hunger Hormones
We naturally produce several different hormones which regulate our appetite, causing us to feel hungry, and to become satiated when we’ve eaten enough. Imbalances in these hormones can cause us to eat more.
The microbiome appears to be able to cause these chemicals to be produced. This makes sense for them, as they depend on us for food. Imbalances in the microbiome can therefore result in higher levels of hunger-producing chemicals.
Insulin Sensitivity and the Microbiome
Insulin is the hormone which tells our cells to take sugar out of the blood and use it for energy. If cells become resistant, or deaf, to the message from insulin, unbalanced blood sugar will be the result. Insulin resistance is a major factor in weight gain and problems losing weight. It seems our gut bacteria are able to influence insulin sensitivity by producing messenger substances.
When gut bacteria were transferred from obese people into normal-weight mice, the mice gained weight, despite eating their normal diet. They also showed metabolic changes similar to those seen in obese people with insulin resistance. Interestingly when the obese mice were rehoused with normal mice again, they lost weight. When animals live communally they naturally pass their gut bacteria to one another. So when the microbiome changed back to normal again, the mice lost the weight they gained.
Inflammation, Weight Gain and Gut Bacteria
Inflammation in the body can itself lead to obesity. Although we may think of inflammation only in connection with a twisted ankle or a sore knee, ongoing chronic inflammation is believed to be at the root of many if not all chronic diseases.
Inflammation can be encouraged by a poor diet, hidden infections and lifestyle choices, but an important regulator of inflammation is the microbiome. Bacteria produce either anti- or pro-inflammatory chemicals, depending on the species residing there. Because obesity can cause further inflammation, it’s a vicious cycle. The way to restore balance is by correcting the microbiome and the chemicals they are producing.
Putting Things Right
If you are trying to lose weight, and you’ve increased your movement, incorporated healthy food choices, had your hormone levels checked and adopted measures to balance your blood sugar, all without success, maybe you should consider taking a closer look at your microbiome.
Functional tests can examine the bacteria residing in your gut along with the messenger chemicals they produce in order to determine which species predominate. If your microbiome is out of balance, a combination of dietary changes and lifestyle modifications can help to restore equilibrium and a diverse range of species.