How Probiotics Promote Immunity
- The immune system becomes more vulnerable to infection and inflammation as we age
- Studies show probiotics protect against infections
- Species of probiotics have been studied for many conditions, including IBS and to fight infections
- Some probiotics stimulate the secretion of an immune protein that helps protect against pathogens, as well as promote a healthy allergic response, modulate the expression of genes and release important natural enzymes
The assortment of all the microorganisms that dwell on and inside our body is collectively known as the human microbiome. The research into our microbiome has exploded over the last couple of decades, has revolutionized how medicine sees humans and how people approach their health and well-being. Historically people were considered separate from the microorganisms that may live in their gut or on their skin. But we now know that the bacteria that make up our microbiome aren’t just passive hitchhikers; they are indispensable for health. In fact, there are 10 times more of them than all of your human cells and without them, you couldn’t live.
The average human provides a home to about 100 trillion microbes, the majority of which make their living in your gut.1 The gut is one of the most densely populated ecosystems on the planet. With so many of them, it’s not surprising that they do a lot of work. Some gut microbes help break down foods and synthesize vitamins. For example, intestinal bacteria synthesize our B vitamins2, help keep inflammation in check3 and a healthy microbiome is associated with higher levels of vitamin D.4
A healthy, plant-based diet and time-restricted eating, also called intermittent fasting, have been shown to change the microbiome, making it healthier and increasing the diversity of organisms.5
This is where probiotics—our friendly bacteria—play an important role. They help maintain balance by keeping unfriendly microbes in check and boosting our immune system in many ways. When an imbalance between friendly and unfriendly organisms develops, you get intestinal dysbiosis. When these unhealthy critters dominate, we are more susceptible to irritable bowel syndrome (IBS), diabetes, obesity, metabolic syndrome, infections, depression, and cancer.6
Our probiotics need nutrients to grow and sustain themselves. This includes certain carbohydrates and fibers that we can’t digest, but our friendly bacteria love. Giving them what they need to be healthy helps us be healthy too. Two groups of important prebiotics are fructooligosaccharides (FOS) and galactooligosaccharides (GOS).7 Prebiotics are frequently found in vegetables, which is why many probiotic dietary supplements will include a prebiotic blend from plants, such as Jerusalem artichoke and chicory root.
As we get older, dysbiosis becomes more common. That’s because medications, diet, stress, and environmental toxins can kill healthy gut bacteria.8 Antibiotics indiscriminately kill good and bad bacteria. When the balance between healthy and unhealthy bacteria gets disturbed, it provides an opportunity for disease-causing species to multiply and create problems. And if you’ve been prescribed multiple rounds of antibiotics, your risk for dysbiosis increases even more.9 Along with antibiotics, acid-blocking medications (eg, Protonix, Prilosec), non-steroidal anti-inflammatories (eg, Tylenol, acetaminophen, Ibuprofen), antipsychotic medications and metformin have also been shown to create dysbiosis and are some of the most common gut killers.10,11
Your Immune System
Older adults are at higher risk for infections, and they die three times as often from infections compared to younger adults. For example, during the flu season, about 90% of flu-related deaths occur in people older than 65.12 Flu vaccines are also not as potent in the elderly.13 Additionally, as people get older the immune system tilts towards inflammation, contributing to the illnesses that are so common we age—cancer, cardiovascular disease, stroke, arthritis, osteoporosis, and dementia.14
Fortunately, there are many ways you can support your immune system and combat “inflammaging.” As the name implies, inflammaging is a chronic, low-grade inflammation that ages you faster. It contributes to osteoporosis, arthritis, heart disease, losing brain cells, and seeing more lines and wrinkles staring back at you in the mirror by destroying collagen. The first step is making sure you’re following a whole foods diet, getting enough sleep, and reducing stress, which is all part of the four pillars of health.
Supplementing with pre- and pro-biotics can also help. Probiotics can suppress pathogens. In fact, molecules secreted by friendly lactic-acid probiotics can reduce the prevalence and virulence of certain highly inflammatory bacteria such as Klebsiella and E. coli.15 A molecule secreted by the probiotic Lactobacillus salivarius prevents mice from succumbing to invasive infections caused by Listeria monocytogenes.16
Probiotics can also help counter the negative effect of antibiotics, including diarrhea. A review of scientific literature on probiotics and GI disorders by the American Gastroenterological Association (AGA) Institute found that may be helpful in reducing the risk fo CDAD (C. difficile associated diarrhea) after antibiotic use.”17
Streptococcus thermophilus, a naturally occurring probiotic, exerts antimicrobial activity by virtue of its production of lactic acid and antibacterial peptides called thermophilins. These can inhibit or kill bacteria. The lactic acid produced by S. thermophilus may reduce pathogen growth. In mice infected with C. difficile, giving them S. thermophilus resulted in 46% less weight loss as compared with mice not taking the probiotic. Taking S. thermophilus was associated with less diarrhea, lower pathology scores, and a decrease in C. difficile toxin production.18 In vitro studies have shown that thermophilins can inhibit many opportunistic and foodborne pathogens, including Enterococcus faecalis, Staphylococcus aureus, Clostridium botulinum, and Listeria monocytogenes.19.20,21,22
Probiotics also support a healthy immune system by stimulating the body’s secretion of immunoglobulin A (IgA). This immune protein helps protect against gastrointestinal infections, as well as reduce allergies, modulate the expression of genes, release important natural enzymes and decrease the ability of pathogens to adhere to the intestinal wall.23
Probiotics have even been demonstrated to improve vaccine response in adults. A review of twenty randomized controlled trials in nearly 2000 adults who took probiotics or prebiotics found the response to flu vaccine was significantly improved over their counterparts who did not consume probiotics and prebiotics.24 In other research on probiotics and response to vaccines, B. bifidum and L. acidophillus increased the response to the gut pathogen Salmonella typhi.25
What You Can Do
- Eat a Whole Foods Diet. It’s important to combine probiotics with a richly nutritious diet with both micro- and macronutrients and all the fiber and nutrition necessary to promote health and healthy gut flora. To help you eat more whole foods, follow the instructions of the blog, 3-Steps to Eating Healthy for Life.
- Take Belly Rescue™ when it launches in October 2021. Belly Rescue promotes a healthy gut micriobiome. It’s potent multi-strain blend of probiotics and prebiotics delivers 25 billion colony forming units (CFU) per serving from 15 strains of health-promoting bacteria. Belly Rescue includes five species of Bifidobacterium, nine species of Lactobacillus and Streptococcus thermophilus. All species used in Belly Rescue have been identity-verified using DNA-fingerprinting technology. Make sure you’re signed up to receive the NBI newsletters so you can be the first to know when Belly Rescue launches.
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