16:8 Fasting Don't restrict your calorie intake during the eating periods. Most of your gut bugs need food to survive—not to mention you need food for energy and other functions—said Devkota. When your body enters starvation mode—like if you fast for too long—you'll decrease the diversity of bacteria in your gut.
Evidence suggests that intermittent fasting may benefit your gut health and boost your gut microbiome, the trillions of bacteria and other microorganisms that live in your gut. Intermittent fasting is an approach to eating where you switch between periods of fasting and eating as normal.
Fasting during prolonged periods gives the gut the time it needs to restore its integrity. This is especially important for those with “leaky gut”, also called intestinal permeability, where the gut lining is weakened thereby allowing toxins, partially digested foods and pathogens to enter the bloodstream.
So to answer the question…to kill off dormant bacteria it can take up to 6 months. This highlights the importance that if any healthy habits are being adopted they must be sustained for at least this amount of time to result in permanent shifts in your microbiome.
Fasting also increased microbial richness (number of different species in the microbiome) and diversity (how diverse and evenly spread out species are), and increased levels of the beneficial SCFA, butyrate8,9,12 which are all generally associated with a healthy gut microbiome.
An anti-inflammatory diet, regular exercise, good quality sleep, and probiotics are all strategies to put in place before trying antimicrobials or antibiotics to get rid of bad bacteria.
Processed foods, as well as alcohol, can also negatively impact gut health. Prebiotic and probiotic foods like whole grains, onions, garlic, fermented foods, miso and yogurt feed the good bacteria in your gut.
What to avoid. As part of healthy eating, it's a good idea to avoid or limit foods packed with added sugar, which feeds bad bacteria, Blatner says, as well as highly processed foods, artificial sweeteners, red meat, and alcohol, which can have a negative effect on gut bacteria, and lead to inflammation.
Many medical experts agree that a one-day fast can feel great, but extending beyond three days can begin to be harmful, especially if you have other medical conditions, such as diabetes or heart disease. “A fast longer than a day or two can deplete vitamins, minerals and electrolytes,” Dr. Hopkins says.
Results. Starvation over 21 days led to increased diversity and altered composition in the intestinal microbiome compared to fed controls, including relative increases in Vibrio and reductions in Plesiomonas bacteria.
We recommend staying on the diet for at least 3-4 weeks as it will take about that long to “heal the gut.” Some patients may take up to 3 months to reestablish a normal functioning intestinal mucosa.
Although the research is scarce, fasting appears to change microbiome composition and, in some cases, boost diversity. Multiple studies also reported an increase in butyrate-producing and mucus-eating bacteria; both considered beneficial.
In order to provide your body with the adequate nutrients, vitamins, minerals, and antioxidants it needs, taking supplements and even probiotics is ideal when you fast. This ensures you don't miss out on the essentials even while you're not eating.
Larance Lab research
“We know that fasting can be an effective intervention to treat disease and improve liver health.
72+ hours. Once you've been fasting for three days or more, your body enters a deep state of ketosis. All the previous benefits: Autophagy, the uptick in the production of beneficial chemicals and hormones, fat loss, and mental clarity continue to increase.
The liver takes up glucose and synthesizes glycogen and triglycerides following food intake, releases glucose produced by glycogenolysis or gluconeogenesis and triggers ketogenesis during fasting (23).
Since we are exposed to numerous factors that hurt our gut microbiome like environmental toxins, constant stress, lack of sleep, antibiotics and high-sugar foods, a daily dose of probiotics is more important than ever. Probiotics help ensure you are maintaining a balance of good bacteria in your intestinal tract.
Drinking plenty of water and staying hydrated is a great way to regulate digestion. Drinking lukewarm water has been shown to be good for digestion as well. Also, try eating plenty of foods high in water content. This includes fruits and vegetables like watermelons, tomatoes, lettuce, and celery.
Coffee also contains phytochemicals that are helpful to the gut and promote the growth of good bacteria, he notes.