Your gastrointestinal tract is not only central to the digestion and absorption of the foods you eat but also is tied heavily to your overall health.
Throughout its length, the gastrointestinal tract is increasingly colonized by microorganisms, known as the gut microbiota. Your gut microbiota describes the different microbe populations present in your large intestine, including bacteria, fungi, viruses, protozoa, and archaea, and the diversity of the microbiota will vary from person to person.
A person has about 300 to 500 different species of bacteria in their digestive tract. It has evolved alongside humans to get to where we are today, living in a mutually beneficial relationship. While some microorganisms are harmful to our health, many are incredibly beneficial and even necessary to a healthy body.
It plays a role in gut function, nutrient absorption, and even fat distribution (1). The gut and its resident microbes are also connected to your immune system, as over 70% of immune cells are in the gastrointestinal tract (2). Therefore, keeping your gut healthy can play a big role in keeping your body healthy.
The incredible complexity of the gut and its importance to our overall health is a topic of increasing research in the medical community. Numerous studies in the past two decades have demonstrated links between gut health and the immune system, mood, mental health, autoimmune diseases, endocrine disorders, skin conditions, and cancer.
Having a wide variety of these good bacteria in your gut can enhance your immune system function, improve symptoms of depression, help combat obesity, and provide numerous other benefits.According to Dr. E. M. Quigley in his studyTrusted Source on gut bacteria in the Journal of Gastroenterology and Hepatology.
The more diverse your gut microbes are, the more able your microbiota is to respond and adapt to changes in the environment improving digestion, a stronger immune system, and potentially a leaner body weight (3, 4).
Many facets of modern life such as high stress levels, too little sleep, the unvaried Western-style diet, comprised mainly of processed foods, and taking antibiotics can all damage our gut microbiome leading to a lack of microbial diversity. This in turn may affect other aspects of our health, like digestion problems and increased risk for weight gain (3-5).
There are a number of ways an unhealthy gut might manifest itself. Here are some of the most common signs:
1. Stomach disturbances
Gas, bloating, constipation, diarrhea, and heartburn can all be signs of an unhealthy gut. A balanced gut will have less difficulty processing food and eliminating waste.
2. A high-sugar diet
A diet high in processed foods and added sugars can decrease the amount of good bacteria in your gut. This imbalance can cause increased sugar cravings, which can damage your gut still further. High amounts of refined sugars, particularly high-fructose corn syrup, have been linked to increased inflammation in the body and inflammation can be the precursor to a number of diseases.
3. Unintentional weight changes
Gaining or losing weight without making changes to your diet or exercise habits may be a sign of an unhealthy gut. An imbalanced gut can impair your body’s ability to absorb nutrients, regulate blood sugar, and store fat. Weight loss may be caused by small intestinal bacterial overgrowth (SIBO), while weight gain may be caused by insulin resistance or the urge to overeat due to decreased nutrient absorption.
4. Sleep disturbances or constant fatigue
The majority of the body’s serotonin, a hormone that affects mood and sleep, is produced in the gut. So an unhealthy gut may contribute to sleep disturbances such as insomnia or poor sleep, and therefore lead to chronic fatigue.
5. Skin irritation
Skin conditions like eczema or acne may be related to a damaged gut. Inflammation in the gut caused by a poor diet or food allergies may cause increased “leaking” of certain proteins out into the body, which can in turn irritate the skin and cause conditions such as eczema.
6. Food intolerances
Food intolerances are the result of difficulty digesting certain foods (this is different than a food allergy, which is caused by an immune system reaction to certain foods). It’s thought that food intolerances may be caused by poor quality of bacteria in the gut. This can lead to difficulty digesting the trigger foods and unpleasant symptoms such as bloating, gas, diarrhea, abdominal pain, and nausea.
A nutrient-rich diet, lowering your stress levels, getting enough sleep, eating slowly, staying hydrated, taking probiotics and digestive enzymes can support your digestive health.
- Shreiner AB, Kao JY, Young VB. The gut microbiome in health and in disease. Curr Opin Gastroenterol. 2015 Jan;31(1):69-75.
- Lebeer S, Vanderleyden J, De Keersmaecker SC. Host interactions of probiotic bacterial surface molecules: comparison with commensals and pathogens. Nat Rev Microbiol. 2010 Mar;8(3):171-84.
- Heiman ML, Greenway FL. A healthy gastrointestinal microbiome is dependent on dietary diversity. Mol Metab. 2016 Mar 5;5(5):317-320.
- Vangay P, Johnson AJ, Ward TL, et al. US Immigration Westernizes the Human Gut Microbiome. Cell. 2018 Nov 1;175(4):962-972.e10.
- Conlon MA, Bird AR. The impact of diet and lifestyle on gut microbiota and human health. Nutrients. 2014 Dec 24;7(1):17-44.