Do you find losing weight hard because all you want to do is eat cake? Do you find making healthy food choices really difficult? Do you feel like you are working out so hard, but the urge to have a chocolate bar on your way home from gym is just too strong? Well, scientists are just starting to find that these food cravings might be coming from your stomach. Sometimes it feels like your stomach has a mind of its own and that if you don’t satisfy the cravings, you just don’t feel good. Some new evidence is emerging to back up that your gut is literally like your second brain.
The Second Brain
Your brain contains neurons that send signals from your body to your brain so that your brain can interpret the data and respond appropriately via neurotransmitters. The brain is a communication hub that coordinates your body to work in perfect harmony. So if your finger is sitting on a hot plate, your nerve endings will detect the heat, send a signal to your brain that will send neurotransmitters to respond and communicate back down to tell your muscles to move your finger away from the heat, tell your vocal chords to yell out and signal your body to apply first aid to your finger. All these complex communications are happening at once via your neural pathways. There are different ways the communications travel too to protect us (for example a quick reflex which by-passes the processing part of the brain to be involved) and more complex communications that require us to problem solve and think about what to do next.
Your gut is like a second brain in that it also contains many of the same neurotransmitters as found in the brain to tell your body what to do next. Your gut also has neurons that are found in the walls of your gut that is called the enteric nervous system. It is a complex communication system that has more neurons than found in your spinal chord. What scientists are discovering is that the enteric nervous system communicates to the brain, which is what they call the ‘gut-brain axis’. It communicates by using hormones and through the vagus nerve, which is connected to your brain stem. This is how your gut can tell you when to eat and what to eat.
Your gut contains approximately 1.5kg of bacteria, these are what we called collectively as gut microbiota. They are able to communicate to the brain via the gut-brain axis. Depending on what you eat and what bacteria you are exposed to in your environment, will depend on what microbiota can be found in your gut. These can be either health bacteria or unhealthy bacteria which cause your body to work against itself to make you feel unwell. So for example, when it comes to making you feel full “a happily functioning gut releases hormones which tell the body that there are nutrients around and everything is fine, and some of these hormones might get into the brain and act on the brain centre which controls feeding and makes you feel satisfied,” says Dr Bertrand.
Bacteria generally want to colonise and grow in number, if you’ve ever tried to fight mould you will understand this idea. As long as the number of healthy bacteria outweigh the number of unhealthy bacteria, your gut will function well and you won’t experience a huge food craving temptation. The more unhealthy bacteria you have living in your gut, the greater their signal is released to the brain to adjust your mood and make you eat foods which will feed them and make their colony bigger. By this theory, gut bacteria is an underlying cause for the epidemic of obesity and weight related illnesses in our society.
How To Reduce Food Cravings
If your gut microbiota can influence the types of food you crave, then it is possible to have some control over your gut to reduce food cravings. There is still a lot of research to be done as most of the studies currently backing this theory is from animals. However, it is making more sense in the human space and there are some things you can do to start having control over your gut.
- Probiotics. These are foods that contain good, healthy bacteria for your gut. Several strains Bifidobacterium and Lactobacillus have been shown to be positive for your gut microbiota. These can be found in yoghurts and fermented foods.
- Prebiotics. These are foods that selectively feed certain good gut bacteria over others, enabling them to culture and become dominant. Onions, garlic, and sweet potatoes are all good prebiotics to include in your diet.
- Enjoy a diverse, nutrient rich diet. By eating foods that contain a lot of nutrients, you can support a wide range of healthy microbiota that will give your gut a good healthy balance of bacteria. Switching to a diverse, nutrient rich diet long term will enable a positive shift to occur in the gut and help those food cravings to subside.
“From a scientific point of view, it’s very clear that the more varied your diet is, the more varied the microbacteria that you support, so if you eat lots of different kinds of foods with different sorts of undigestable products, that supports a more diverse microbacterial community in your gut and that’s been associated with good health and a more robust ability to resist stress and change.” -Dr. Bertrand.