The high fiber group increased their intake from Finally, the participants had 4 weeks during which they could continue the diet if they chose to. Throughout each stage of the study, the researchers continued to collect blood and stool samples. The stool samples enabled them to identify any changes to the gut microbiome of the participants, while the blood samples revealed any fluctuations in key biological markers of inflammation and general health.

After analyzing the data, the researchers found that the diversity of the gut microbiomes of the participants who were on the fermented food diet markedly increased.

According to Dr. Justin Sonnenburg, Ph. It provides one of the first examples of how a simple change in diet can reproducibly remodel the microbiota across a cohort of healthy adults. The researchers also found that for the people who were on the fermented food diet, 19 inflammatory proteins decreased, and four types of immune cell had less activation.

Another corresponding author, Prof. Christopher Gardner, Ph. In contrast, the participants on the fiber diet saw no changes to the diversity of their gut microbiome and no decrease in the 19 inflammatory proteins.

Erica Sonnenburg, Ph. The data suggest that increased fiber intake alone over a short time period is insufficient to increase microbiota diversity.

The researchers noticed that participants on the high fiber diet had more carbohydrates in their stool samples. This suggests that the participants did not have the right gut microbes to break down the fiber fully.

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Medical News Today. Health Conditions Health Products Discover Tools Connect. Could fermented foods improve microbiome diversity? By Timothy Huzar on July 17, — Fact checked by Hilary Guite, FFPH, MRCGP. Share on Pinterest A new study investigates how fermented foods, such as kombucha pictured , might affect gut bacteria.

Gut microbiome. Fiber and fermentation. Fermented food increased diversity. There are no official recommendations for how often you should eat fermented foods, but research suggests that regularly including them into your diet may help bolster gut health and fight inflammation.

One small study reported that people who consumed six servings of fermented foods daily for 10 weeks experienced significant reductions in inflammatory markers and an increase in gut microbiome diversity compared to study participants who doubled their dietary fiber intake and did not eat fermented foods during the trial.

Whether you need to consume six servings of fermented foods every day in order to reap their benefits remains to be seen. For now, try incorporating at least one fermented food into your diet daily by enjoying kefir at breakfast, sipping on some kombucha with lunch, or adding a spoonful of sauerkraut to a grain bowl at dinner.

To properly ferment foods at home, you will need sterilized glass jars, salt, a cloth napkin or cheesecloth, and whatever ingredients you intend to ferment. Here are general steps for making fermented vegetables at home:. Common side effects of eating fermented foods can include digestive symptoms, such as abdominal bloating and gas, in sensitive individuals.

Preparing fermented foods at home without following proper food safety standards such as not washing your hands properly or not using sterilized jars can increase the risk of harmful microbes growing in your food. Improper storage of fermented foods can also heighten the risk of contracting a foodborne illness after consumption.

Eating fermented foods may also pose risks for people diagnosed with a histamine intolerance, those who suffer from migraines , and individuals taking monoamine oxidase inhibitors MAOI medications.

If this is you, talk to your healthcare provider about whether regularly eating fermented foods is safe for you. Fermented ingredients are those that are produced with microorganisms such as bacteria or yeast and undergo chemical changes as a result.

Some ingredients are fermented but do not contain any active bacteria. Here are a few examples:. Other fermented foods contain active bacteria, but have not yet been confirmed to act as probiotics. According to the International Scientific Association of Probiotics and Prebiotics, in order for a fermented food to be accurately labeled as a probiotic, it must:.

If fermented foods are new to you, start slowly by incorporating one to two servings of fermented foods daily to assess your tolerance.

Most fermented foods are full of compounds that help fight inflammation, as well as important vitamins and minerals,. Dimidi E, Cox SR, Rossi M, Whelan K. Fermented Foods: Definitions and Characteristics, Impact on the Gut Microbiota and Effects on Gastrointestinal Health and Disease. Shahbazi R, Sharifzad F, Bagheri R, et al.

Anti-inflammatory and immunomodulatory properties of fermented plant foods. Elkashty OA, Tran SD. Sulforaphane as a promising natural molecule for cancer prevention and treatment. Curr Med Sci. Monash University. Fermented foods and FODMAPS.

Kwak SH, Cho YM, Noh GM, et al. Cancer preventive potential of kimchi lactic acid bacteria Weissella cibaria, Lactobacillus plantarum. J Cancer Prev. Subali D, Christos RE, Givianty VT, et al. Soy-based tempeh rich in paraprobiotics properties as functional sports food: more than a protein source.

Siciliano RA, Reale A, Mazzeo MF, et al. Paraprobiotics: a new perspective for functional foods and nutraceuticals. FoodData Central. Bellikci-Koyu E, Sarer-Yurekli BP, Karagozlu C, et al.

Probiotic kefir consumption improves serum apolipoprotein A1 levels in metabolic syndrome patients: a randomized controlled clinical trial. Nutr Res. Farag MA, Jomaa SA, El-Wahed AA, et al. The many faces of kefir fermented dairy products: quality characteristics, flavour chemistry, nutritional Value, health benefits, and safety.

Hadjimbei E, Botsaris G, Chrysostomou S. Beneficial effects of yoghurts and probiotic fermented milks and their functional food potential. Cao ZH, Green-Johnson JM, Buckley ND, et al.

Bioactivity of soy-based fermented foods: a review. Biotechnol Adv. Saeed F, Afzaal M, Shah YA, et al. Food Sci Nutr. Wastyk HC, Fragiadakis GK, Perelman D, et al. Gut-microbiota-targeted diets modulate human immune status.

National Institutes of Health. Probiotics fact sheet for health professionals. Marco ML, Sanders ME, Gänzle M, et al. The International Scientific Association for Probiotics and Prebiotics ISAPP consensus statement on fermented foods.

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Kimchi is a traditional fermented Korean dish that is made from vegetables, including cabbage, plus spices like ginger, garlic, pepper and other seasoning. Goat milk , sheep milk and A2 cows soft cheeses are particularly high in probiotics, including thermophillus, bifidus, bulgaricus and acidophilus.

The label should indicate that the cheese is raw and has been aged for six months or more. Yogurt and kefir are unique dairy products because they are highly available and some of the top probiotic foods that many people eat regularly.

Probiotic yogurt is now the most consumed fermented dairy product in the United States and many other industrialized nations too. It also contains certain types of acids like acetic acid, which supports the function of probiotics and prebiotics in your gut.

You can add one tablespoon of apple cider vinegar to a drink twice a day. Before breakfast and lunch or breakfast and dinner, add one tablespoon of apple cider vinegar in your meal, and then start consuming more fermented vegetables like sauerkraut and kimchi or drinking kvass to really boost probiotic levels.

Kvass is a traditional fermented beverage that has a similar taste to beer. Much like kombucha, it goes through a fermentation process and contains probiotics.

The longer it ferments, the more susceptible it is to becoming more alcoholic. Sometimes it is brewed with flavors from fruits such as raisins and strawberries and herbs such as mint to make it more appealing.

Fermentation helps make nutrients found in the grains more available for absorption and reduces antinutrient content that may make digestion difficult.

Because more research is confirming that probiotics are highly beneficial, food manufacturers are beginning to make probiotic dairy products such as cottage cheese more readily available.

Similar to yogurt, cottage cheese can be fermented when bacteria help break down the lactose a type of sugar in the dairy. When purchasing cottage cheese , look for brands that are low in sugar and that contain active cultures. Try it in smoothies, in baked goods, with fruit, on its own, etc.

Just opt for brands that are low in sugar or unflavored, and consider adding your own stevia, fruit or honey for extra flavor.

Why are fermented foods good for you? The consumption of fermented, probiotic foods has many positive effects on not only the digestive system, but basically the whole body.

The microbes that we obtain from eating probiotic foods help create a protective lining in the intestines and shield against pathogenic factors , such as salmonella and E. They may also represent a potential avenue to counter the pro-inflammatory effects of gut dysbiosis. Fermented foods nutrition is also important for increasing antibodies and building a stronger immune system.

Plus, these foods regulate the appetite and reduce sugar and refined carb cravings. Another benefit is that lacto-fermentation enhances the nutrient content of foods and makes the minerals in cultured foods more readily available.

Recent research spearheaded by the University of Maryland School of Social Work found a link between social anxiety disorder and gut health. A big part of our emotions seem to be influenced by the nerves in our guts the enteric nervous system.

In animal studies, depression has been found to be linked to the interplay of the brain and gut health, and people with chronic fatigue syndrome have also been found to benefit from probiotic consumption.

What are fermented foods exactly? The fermentation of foods such as milk and vegetables is also a great way to preserve them for a longer period of time and to make their nutrients more bioavailable absorbable. Lactic acid decreases pH of milk, causes it to clot and thicken, and gives it a smooth texture.

After fermentation, yogurt contains the characteristic bacterial cultures called Lactobacillus bulgaricus and Streptococcus thermophilus. Lactobacillus bulgaricus and Streptococcus thermophilus are the only two cultures required by law to be present in yogurt.

Kefir and yogurt are made in a similar way, but the two are a bit different because kefir is made at room temperature with continuous use of kefir grains, which contain a variety of bacteria and yeast. Most fermented vegetables are cultured via the process of lactic acid fermentation or lacto-fermentation , which occurs when veggies are chopped and salted.

Fermented veggies contain high acidity and low pH that usually make them shelf-safe and safe to consume for longer than fresh vegetables.

Many fermented vegetables are also made with additional ingredients like coriander, garlic, ginger and red pepper, which also offer various health benefits.

The exact microbial counts found in fermented veggies depend on the nutrient status of the fresh produce used and varies with seasons, maturity stage, environmental humidity, temperature and the use of pesticides, among other factors.

This gives your gut time to adjust to the presence of new bacteria. Yogurt is widely available, and other fermented foods like kefir, sauerkraut and kimchi are becoming easier to find. Look for fermented foods in health food stores, large supermarkets and at your local farmers market.

What foods can you ferment at home? The list is long and includes many vegetables, grains, soybeans, milk, etc. For example, fermented vegetables you can prepare at home include cabbage, carrots, green beans, turnips, radishes and beetroots. Here is a basic homemade fermented foods recipe using vegetables you may already have on hand you can learn more about making cultured veggies by checking out this homemade sauerkraut recipe :.

When making certain fermented food you may require the use of kefir grains, whey, yeast or a starter culture, depending on the exact recipe and your personal taste.

You can refer to the Cultures for Health website for specific recommendations. These provide probiotics along with essential vitamins and minerals, and they can supply salt, which is needed on the keto diet to balance water loss.

A small amount of full-fat ideally raw dairy products, such as unsweetened yogurt or kefir, may also be consumed on the keto diet. Just be sure to avoid any product that is sweetened with fruit, sugar, etc.

A healthy Ayurvedic diet includes fermented foods, such as yogurt, amasai and miso. Many different seasonal vegetables may be fermented to prolong how long they are edible, such as asparagus, beets, cabbage, carrots, cilantro, fennel root anise , garlic, green beans, etc.

Ayurvedic and Indian fermented foods are often combined with anti-inflammatory herbs and spices. These include turmeric, cumin, fennel, ginger, cardamom , coriander , cinnamon, clove, rock salt, mint, black pepper and oregano. Fermented foods are especially encouraged for vata types, who can benefit from foods that have a natural sour and salty taste, rather than those that are bitter, pungent and astringent.

For example, the key enzymes needed to form vitamin B12 are only found in bacteria, not in plants and animals. Sugars like table sugar and lactose milk sugar are quickly absorbed in the upper part of the small intestine, but more complex carbohydrates like starches and fibers are not as easily digested and may travel lower to the large intestine.

There, the microbiota help to break down these compounds with their digestive enzymes. The fermentation of indigestible fibers causes the production of short chain fatty acids SCFA that can be used by the body as a nutrient source but also play an important role in muscle function and possibly the prevention of chronic diseases, including certain cancers and bowel disorders.

The microbiota of a healthy person will also provide protection from pathogenic organisms that enter the body such as through drinking or eating contaminated water or food.

Large families of bacteria found in the human gut include Prevotella , Ruminococcus , Bacteroides , and Firmicutes. If microbiota are so vital to our health, how can we ensure that we have enough or the right types?

You may be familiar with probiotics or perhaps already using them. These are either foods that naturally contain microbiota, or supplement pills that contain live active bacteria—advertised to promote digestive health.

Whether you believe the health claims or think they are yet another snake oil scam, they make up a multi-billion dollar industry that is evolving in tandem with quickly emerging research.

Allan Walker, Professor of Nutrition at the Harvard Chan School of Public Health and Harvard Medical School, believes that although published research is conflicting, there are specific situations where probiotic supplements may be helpful.

Because probiotics fall under the category of supplements and not food, they are not regulated by the Food and Drug Administration in the U.

This means that unless the supplement company voluntarily discloses information on quality, such as carrying the USP U.

Pharmacopeial Convention seal that provides standards for quality and purity, a probiotic pill may not contain the amounts listed on the label or even guarantee that the bacteria are alive and active at the time of use.

In addition to family genes, environment, and medication use, diet plays a large role in determining what kinds of microbiota live in the colon. A high-fiber diet in particular affects the type and amount of microbiota in the intestines.

Dietary fiber can only be broken down and fermented by enzymes from microbiota living in the colon. Short chain fatty acids SCFA are released as a result of fermentation.

This lowers the pH of the colon, which in turn determines the type of microbiota present that would survive in this acidic environment. The lower pH limits the growth of some harmful bacteria like Clostridium difficile.

Growing research on SCFA explores their wide-ranging effects on health, including stimulating immune cell activity and maintaining normal blood levels of glucose and cholesterol. Foods that support increased levels of SCFA are indigestible carbohydrates and fibers such as inulin, resistant starches , gums, pectins, and fructooligosaccharides.

These fibers are sometimes called prebiotics because they feed our beneficial microbiota. Although there are supplements containing prebiotic fibers, there are many healthful foods naturally containing prebiotics.

The highest amounts are found in raw versions of the following: garlic, onions, leeks, asparagus, Jerusalem artichokes, dandelion greens, bananas, and seaweed. In general, fruits , vegetables , beans , and whole grains like wheat, oats, and barley are all good sources of prebiotic fibers.

Be aware that a high intake of prebiotic foods, especially if introduced suddenly, can increase gas production flatulence and bloating. Individuals with gastrointestinal sensitivities such as irritable bowel syndrome should introduce these foods in small amounts to first assess tolerance.

With continued use, tolerance may improve with fewer side effects. If one does not have food sensitivities, it is important to gradually implement a high-fiber diet because a low-fiber diet may not only reduce the amount of beneficial microbiota, but increase the growth of pathogenic bacteria that thrive in a lower acidic environment.

These include fermented foods like kefir, yogurt with live active cultures, pickled vegetables, tempeh, kombucha tea, kimchi, miso, and sauerkraut. The microbiome is a living dynamic environment where the relative abundance of species may fluctuate daily, weekly, and monthly depending on diet, medication, exercise, and a host of other environmental exposures.

The contents of this website are for educational purposes and are not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

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