29.JAN.2019 3 MIN READ | 3 MIN READ

The bacteria in your gut determine how well you digest your food, and can also have an impact on your weight and health.

What is gut bacteria?

Bacteria are microbes, like viruses or fungi, and are simple single-celled organisms. There are actually around 10 times more bacteria in your body than human cells, and most of them are found in your gut. Your combination of microbes is called your microbiome or microbiota, and is unique to you. While bacteria can be found everywhere in your body, scientists believe the bacteria in your gut plays an important role in your health.

What does gut bacteria do?

Gut bacteria Gastro health

The bacteria in your digestive system have several roles to play in the way your body functions. Some of them:

  • Synthesise essential nutrients, including vitamin K, vitamin B12 and biotin
  • Develop and regulate your immune system
  • Support the development of gastrointestinal health

Research suggests that the overall balance of bacteria in your digestive system has an impact on your health and your susceptibility to a range of diseases and conditions.

How does gut bacteria affect my appetite?

Hormones are produced by your body that control whether you feel hungry or full, such as leptin, ghrelin, and peptide YY. Leptin helps to suppress appetite in the brain, while peptide YY acts to reduce food intake. On the other hand, ghrelin is the hunger-stimulating hormone, which works on a cycle, rising before meals and dropping after meals. Some studies showed certain chain reactions caused by gut bacteria have been shown to affect the production of these hormones and therefore control your appetite. Some species of gut bacteria produce short-chain fatty acids such as propionate when they break down fibre.

What are some other health impacts of gut bacteria?

Gut bacteria Insulin resistance

Preliminary research shows that gut bacteria potentially have a significant impact on the presence of a number of diseases. Gut bacteria may hold the key to improving the wellbeing of people with many conditions, including:

  • Crohn's disease
  • Ulcerative colitis
  • Insulin resistance
  • Colon cancer

What should I eat to increase good bacteria in my gut?

The following foods contain good bacteria or support the growth of good bacteria in your gut:

  • Fermented foods (eg. tempeh – a fermented soybean cake, kombucha, sauerkraut, kimchi, miso and yoghurt)
  • Foods that are high in prebiotic fibre (eg. legumes, oats, bananas or onions)
  • Whole grains
  • Green tea
  • Cultured drinks

Probiotic supplements are another way to improve your gut health, because they are live bacteria that help to replace or balance your system. They are often recommended after you take a course of antibiotics, which deplete your resources. Your doctor or a dietitian will be able to advise if you should take a probiotic supplement.

What else can I do for my gut?

Gut bacteria Healthy lifestyle
The best thing you can do to maintain a healthy gut and a healthy weight is to live a healthy lifestyle. Besides eating a balanced diet, you should exercise regularly, quit smoking, manage stress and get enough sleep. It’s also important to avoid unnecessary courses of antibiotics, and to take a probiotic if your doctor thinks it is needed. All of these things will benefit your overall health, and leave you with a happy tummy full of good bacteria.

Article reviewed by Lee Sze Mien, dietitian at Mount Elizabeth Hospital


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Lee Sze Mien
Mount Elizabeth Hospital

Ms Lee Sze Mien is an accredited dietitian with the Singapore Nutrition & Dietetics Association.