Most of us associate myalgia or muscular weakness with overexertion or muscle strain. But an unhealthy gut or gastrointestinal issues can also hamper muscle health, say experts.
The connection between gut health and muscle health is pretty direct. The processes involved in nutrient absorption, energy production and immune function, necessary for muscle growth and repair, are supported by a healthy gut microbiome (the microorganisms that make up a person’s digestive system).
“The gut microbiome, consisting of healthy bacteria, is crucial because it aids in digestion and absorption,” says Dr K Amilthan, senior consultant, general and laparoscopic surgery, Dr Mehta’s Hospital, Chennai. “The food we eat or the water we drink will not be adequately absorbed if the right bacteria are not present in the stomach.”
By making it more difficult for the body to properly extract and utilize the vital nutrients needed for muscle health, growth and repair, limited absorption and digestion can contribute to muscle depletion, and may manifest as muscle weakness and fatigue.
Gut issues that harm muscles
Muscle nourishment is significantly influenced by a healthy gut microbiome. Along with that, gastrointestinal issues can harm the muscles.
“If your gut health is impaired due to a simple cause like acute diarrhea or a long-term condition like inflammatory bowel disease, it can affect nutrient absorption,” says Dr Rupesh Kalyan, consultant medical gastroenterologist, Bengaluru. “The various nutrients that we consume are absorbed at various places in the intestines. If it does not happen, your muscles will lose strength and your muscles are bound to get fatigued easily.”
Cancer in the gut (bowel cancer) severely impacts muscle health. “Cancer in the gut may disrupt a person’s ability to absorb nutrients from the diet,” adds Dr Kalyan. “It can lead to cachexia, a disorder that causes muscle wasting, weakness and decreased muscle mass. Weight loss, muscle loss and systemic inflammation are symptoms of cachexia.”
How dehydration affects the gut and muscles
To describe how dehydration affects the gut, and thereby the muscles, Dr Amilthan talks about intracellular and extracellular volumes (terms used to explain how fluids are distributed throughout the body). “Intracellular volume is the fluid within each cell of the body, and extracellular volume is the fluid present outside the cells,” says Dr Amilthan.
Intracellular and extracellular volumes are crucial within the gut. While intracellular fluid provides the environment required for cellular functions, including metabolism and nutrient exchange, the transport of nutrients, gases and waste materials between cells, blood vessels and the digestive system is made easier by the extracellular fluid.
“Lack of fluid intake causes the fluid inside cells (intracellular volume) to leak out and enter the extracellular volume,” says Dr Amilthan. “The fluid inside the cell eventually shrinks as a result. It leads to cramping in the muscles. The same thing takes place if you drink alcohol. Alcohol is a diuretic; it causes frequent urination and causes cell shrinkage.”
Takeaways
- A healthy gut microbiome supports nutrient absorption, energy production and immunological function, all of which are required for muscle growth and repair.
- Gut conditions ranging from minor to severe — including acute diarrhea and inflammatory bowel disease — can hinder nutrient absorption and negatively impact the muscles.
- In some instances, dehydration can lead to shrinkage of the cells, resulting in muscle pain.
