Your intestines are home to trillions of microorganisms that help break down food and produce essential nutrients like B vitamins and vitamin K. Fasting can be a beneficial way to support these microorganisms and improve overall gut health.
The Benefits of a Healthy Gut
When your gut bacteria digest dietary fiber, they create compounds critical for muscle function and disease prevention. These bacteria also influence your emotions and cognition through the gut-brain axis, the connection between your brain and digestive system.
Feeding your gut microbes the right nutrients helps balance the good and bad bacteria, providing significant health benefits. A healthy gut microbiome can reduce the risk of chronic conditions such as:
- Asthma
- Chronic kidney disease
- Diabetes
- Heart disease
- Irritable bowel syndrome
- Mental health conditions
- Rheumatoid arthritis
What Is Intermittent Fasting?
Intermittent fasting (IF) is an eating pattern where you eat only during specific parts of the day. There are various methods of IF, such as:
Time-restricted feeding: Eating within a certain number of hours each day and fasting the rest of the time.
Weekly IF: Limiting food intake on two to three nonconsecutive days per week.
Research indicates that IF can lead to weight loss and improved metabolic function, potentially lowering the risk of diabetes and cancer. However, most studies have been conducted on rodents, and human studies have had mixed results, so more research is needed to determine the effectiveness of these approaches.
Note: Pregnant or breastfeeding individuals and those with a history of disordered eating should not try any form of fasting.
Intermittent Fasting and Gut Health
IF can enhance your metabolism’s efficiency and diversify your gut microbiome. It can increase the presence of Akkermansia muciniphila, a bacteria associated with reduced intestinal inflammation and a healthier gut barrier. This gut barrier allows nutrients to pass through while blocking harmful bacteria and germs.
“Your gut bacteria are very responsive to the presence and absence of food,” says Suzanne Devkota, PhD, director of microbiome research at Cedars-Sinai in Los Angeles. “When you remove food, the microbiome shifts in composition.”
Tips for Gut Health Fasting
Common IF patterns include:
- 5:2 weekly fasting: Eat normally for five days and restrict calorie intake for two nonconsecutive days.
- 16:8 time-restricted feeding: Fast for 16 hours and eat during the remaining eight hours.
Fasting days don’t have to be completely devoid of calories. Plans typically recommend a 70% to 75% reduction in calories on fasting days, but even a 60% reduction can be beneficial. It’s also essential not to restrict calorie intake during eating periods but focus on portion control.
Short-term fasting has no negative effect on gut diversity. However, prolonged fasting can decrease bacterial diversity, so ensure your fasting is truly intermittent and avoid fasting for two consecutive days.
Eating by the Clock
Aligning your fasting regimen with your natural sleep/wake cycles, like a 16:8 or 14:10 breakdown, can be beneficial. Circadian rhythms regulate nutrient processing, and insulin is most effective in the morning and midday. Eating breakfast a bit later and dinner earlier can help you align your food intake with your circadian rhythm, allowing for a prolonged overnight fast without too much effort.
