The Role of Fermented Foods in Gut Health
Gut health is a buzzword in the health and wellness
industry these days, and for good reason! Your microbiome, or the gut flora
that inhabit your digestive system, plays a crucial role in overall health. The
microbiome is composed of bacteria, viruses, and fungi in a 10:1:1 ratio.
Trillions of these little critters make up an individual’s unique microbiome,
which is what sets the foundation for health. Overall health starts in the gut,
and the composition and relationships between the microorganisms central to the
gut play a huge role in determining how we feel on a day-to-day basis. Our
microbiome and its balance have a massive impact on immune function, digestive
capabilities, and mental health, as well as the way genes are expressed.
Our lifestyles, diets, medications, environmental
influences, and even the way we were born, nursed, or reared will determine the
composition of our microbiome and affect the optimal functioning of our
day-to-day health. An unhealthy or unbalanced microbiome can also spell the
onset of a variety of diseases, mostly centered around the digestive system.
Issues can range from a minor digestive issue that causes discomfort to chronic
and severe conditions. Crohn's disease, ulcerative colitis, heartburn, gastroesophageal
reflux disease, small intestinal bacterial overgrowth, celiac disease, and
irritable bowel syndrome are just a few of the more common gastrointestinal
disorders that arise from an imbalanced gut. Clearly, there is great importance
in having a well-balanced and healthy microbiome. Gastrointestinal diseases
aside, the microbiome has also been linked anecdotally and scientifically with
other conditions ranging from skin health, endometriosis, polycystic ovarian
syndrome, mental health, and more. More research is needed to draw stronger
conclusions, yet it is noted that these conditions often report improvements
when balancing the microbiome and improving overall gut health.
1. Fermentation Process and Types of Fermented Foods
Fermentation is the process whereby food or drink
undergoes transformation by the activity of microorganisms. There are a variety
of different fermentation techniques and types of food and beverages being
produced. Generally, sugars are broken down by microorganisms such as bacteria,
yeast, or mold in order to produce a range of compounds including, but not
limited to, lactic acid, alcohol, hydrogen peroxide, and carbon dioxide. This
process often results in food preservation and the development of characteristic
features such as changes in nutritional and sensorial properties. Some commonly
consumed fermented foods include kefir, yogurt, sourdough, miso, tempeh,
pickles, sauerkraut, kimchi, kombucha, and chocolate, among others. There are
many different types of food and drink produced, as well as different
techniques of fermentation used, around the world as a result of cultural and
biological diversity.
Fermented foods are important components of the human
diet globally, not only for their unique sensory attributes and nutritional
contributions but also for their functional and health-promoting properties.
For instance, fermenting foods can break down compounds that cause digestive
discomfort, resulting in an improvement in the digestibility of fermented
foods. In addition, managing fermentation variables such as salt
concentrations, pH, temperature, oxygen content, and fermenting time may favor
the growth of desirable microbial species with the potential of developing new
functional ingredients. Fermentation is also used to improve the nutritional
profile, sensory characteristics, flavor, shelf life, and antimicrobial
activity of certain foodstuffs. The consumer demand for natural, functional
foods with healthy ingredients and non-critical processes has also motivated
the reevaluation of fermentation.
2. Impact of Fermented Foods on Gut Health
To influence and promote healthy gut microbiota, many
believe that increasing the consumption of fermented food products will provide
beneficial microorganisms. Fermented foods such as kimchi, sourdough bread,
kefir, yogurt, and lacto-fermented pickles can contain an array of beneficial
microorganisms. Increased consumption of fermented foods has been associated
with a more diverse assortment of microorganisms in the gut of the consumer.
Fermented foods can also promote the growth of gut flora: after being processed
by enzymes, beneficial bacteria ferment food products and create short-chain
fatty acids and gases. These acids and gases can increase beneficial lactic
acid bacteria. Moreover, the fermentation process makes the nutrients present
in food more digestible, meaning they are a good option for people with
digestive problems.
Probiotics are live microorganisms found in some
fermented foods that benefit the consumer by improving their digestive function
and overall health. Some probiotics may also improve the villi: the small
finger-like projections lining the small intestine that help nutrient
absorption. A number of studies have supported the consumption of fermented
foods for good gut health, with one finding that fermented kimchi was able to
alter the overall microbial community and lower the levels of inflammation
within the gut. Some key features found to support good digestive function
included weight control, irritation reduction, liver improvement, depression,
and mental health. Specifically, probiotics are recognized for their
contributions to the prevention or relief of inflammation, enhancement of
immune function, and reduction of bad bacteria, including those causing
diarrhea. Fermented foods offer mechanisms to deliver these important
properties to the digestive system. However, individual differences in how gut
flora affects people do exist, and not everyone’s gut flora responds the same
way to different fermented products. To help combat this, regular dietary
regeneration with new fermented food products should be implemented.
3. Fermented Foods and Digestive Disorders
While it is important to acknowledge that there is
emerging research supporting the potential benefits of fermented foods in the
management of gastrointestinal (GI) diseases and disorders, this field is still
in its relative infancy. Research exploring the effects of fermented foods on
the clinical health of individuals with GI disorders or food intolerances is
currently focusing on IBS and IBD, which may progress to various systemic
diseases. A body of clinical data is accumulating and supports a potential
mechanism of action for the improvement of GI symptoms linked to the
consumption of probiotics and prebiotics in fermented foods: their action as
agents to regulate the GI environment, including gut microflora, and ensure
that ferments are free from potential pathogenic microbes. Irritable Bowel
Syndrome and Inflammatory Bowel Disease. Clinical improvements in individuals
with IBS and IBD have been noted with the consumption of FODMAPs in general.
Improved health outcomes include decreased digestive symptom severity,
including improvements in IBS symptom sub-indices; improved clinical signs and
inflammatory markers. Collectively, these clinical benefits from well-planned
and properly conducted research lead us to further hypothesize that fermented
foods are likely to assist in the regulation of digestive and gut function.
Further food studies and the analyses of other potential mechanisms of action
via bacteria and purines are now being planned to identify whether fermented
foods can act beyond the low FODMAP dietary framework to enhance gut health.
4. Practical Tips for Incorporating Fermented Foods into the Diet
There are many ways to include different types of
fermented foods into daily meals and snacks. For instance, you can add yogurt
to your smoothie; use labneh as a base for a mixed toppings plate; use kimchi
or sauerkraut as a unique condiment on a salad or bowl, or snack on these
items. Fermented black garlic can be chopped and eaten on top of hummus as a
creamy topping option. In the morning, or any time of day, you can spread cream
cheese on your favorite bread and top it with fermented items. Adding miso to
your favorite pesto, soup, or marinade is another option. Starting with just
1-2 tablespoons in a recipe is great! To make sure your body is able to digest
these foods effectively and isn’t overwhelmed with the introduction of new
probiotics, it’s often helpful to start by incorporating 1 tablespoon of a
fermented food per day and gradually increase intake. For individuals who are
new to different types of probiotics, it may be especially helpful to avoid
consuming a probiotic supplement in addition to a fermented food until the body
has had a chance to adjust.
If purchasing fermented foods from a grocery store,
look for products that are rich in live, active cultures in order to fully
harness their probiotics. For yogurts, this means avoiding products that have
undergone heat pasteurization post-culturing. Additional tips for purchasing
fermented foods include avoiding products with an excess of added sugars,
looking for organic options, and purchasing refrigerated items. For those who
are vegan or lactose intolerant, consider coconut milk yogurt (which does have
active live cultures), and various fermented vegetable products such as
sauerkraut, kimchi, and fermented black garlic. For the most part,
recommendations for fermented foods focus on eating a range. In summary, enjoy
your fermented food wherever possible, but don’t rely only on these for
post-meal probiotics.