TAG | Probiotics
The liver is the body’s powerhouse of detoxification. The main function of the liver is to filter blood that comes directly from the intestines to the liver via the portal vein. The health of the liver, therefore, is very much dependent on the health of the gut. The intestinal lining is the main interface between the immune system and the external environment, and the health of the intestinal lining is determined by its balance of bacteria. When gut bacteria are out of balance, the intestinal lining can become damaged. As a result, a higher amount of toxins are able to pass through the lining and into the bloodstream, accessing the immune system as they travel directly to the liver for processing.
Because of the close proximity and intimate relationship between the gut and the liver, conditions that affect the liver are being increasingly linked to gut bacterial disturbances. There are two main ways in which researchers believe that gut bacteria contribute to non-alcoholic fatty liver disease (NAFLD), as discussed in a recent review paper published in the Journal of Functional Foods:
- Increased production of ethanol (alcohol) by gut bacteria2
- Increased absorption of bacterial toxins (such as lipopolysaccharide, or LPS)3
These toxins trigger inflammation in the liver via upregulation (increase) of immune function, which initiates the development of NAFLD. These toxins more readily flow to the liver under three main conditions, all known to be contributing risk factors of NAFLD:
- Leaky gut (increased intestinal permeability)
- Small-intestinal bacterial overgrowth (SIBO), a form of dysbiosis in which bacteria from the colon back up into the small intestine and overgrow.
- Bacterial translocation, or the migration of bacteria from the gut through the intestinal lining and into the mesenteric lymph nodes, where they trigger inflammation that reaches the liver.
To reverse or prevent the harmful effects of gut bacterial disturbances on the liver, probiotic administration has been suggested. The researchers note the following possible mechanisms by which probiotics can improve NAFLD:
- Decreased inflammation
- Decreased SIBO
- Immune system regulation
- Decreased LPS production
- Decreased bacterial translocation
An important function of probiotics is the protection of the intestinal lining. This function explains the protective functions of these beneficial bacteria. In a human clinical trial, patients with non-alcoholic steatohepatitis (NASH)—a condition that often follows NAFLD—received a multi-strain, high-dose probiotic and were found to have significant decreases in inflammation and improvements in levels of the liver enzyme aminotransferase.4 In another uncontrolled trial on the same probiotic formula, NAFLD and alcoholic cirrhosis patients experienced decreased inflammation and lipid peroxidation.5 In another clinical trial, the probiotics Lactobacillus bulgaricus and Streptococcus thermophilus supplementation resulted in improved liver aminotransferase levels in people with NAFLD.6
“Probiotics, as safe and effective compounds, have the potential to influence gut barrier functions and immune cell regulations resulting in liver health improvements,” noted the researchers.
Due to the scarcity of treatments available for NAFLD, probiotics are a promising option. More studies are needed to further pinpoint just how the probiotics exert their benefits in people with fatty liver disease.
- Mohammedmoradi S, Javidan A, and Kordi J, “Boom of probiotics: This time non-alcoholic fatty liver disease—A mini review.” J Functional Foods. 2014 Nov;11:30–35.
- Compare D, Coccoli P, Rocco A, et al., “Gut—liver axis: the impact of gut microbiota on non alcoholic fatty liver disease.” Nutr Metab Cardiovasc Dis. 2012 Jun;22(6):471–6.
- Vanni E and Bugianesi E, “The gut-liver axis in nonalcoholic fatty liver disease: Another pathway to insulin resistance?” Hepatology. 2009 Jun;49(6):1790–2.
- Loquicercio C, De Simone T, Fe3derico A, et al., “Gut-liver axis: a new point of attack to treat chronic liver damage?” Am J Gastroenterol. 2002 Aug;97(8):2144–6.
- Loquicercio C, Federico A, Tuccillo C, et al., “Beneficial effects of a probiotic VSL#3 on parameters of liver dysfunction in chronic liver diseases.” J Clin Gastroenterol. 2005 Jul;39(6):540–3.
- Aller R, DeLuis DA, Izaola O, et al., “Effect of a probiotic on liver aminotransferases in nonalcoholic fatty liver disease patients: a double blind randomized clinical trial.” Eur Rev Med Pharmacol Sci. 2011 Sep;15(9):1090–5.
Early life is a critical development period in many respects, and particularly as it relates to gut microbial composition. Even before birth, gut microbes are transferred from mother to fetus, a transfer that continues during birth and later via breast milk. Once established, gut microbes in the infant play a protective role on the infant’s health.
A disturbance of gut microbial balance during early development has been linked to obesity. Epidemiological studies have found that exposure to antibiotics during infancy can lead to weight gain later in life.1-3 Animal studies have confirmed this link and determined that low-dose antibiotics administered after weaning lead to an increased fat mass, altered metabolic hormones, liver metabolism, and microbiota composition.4
A recent study published in the journal Cell followed up this research and confirmed that the increased fat mass was the result of changes in gut bacteria and not to the antibiotic itself.5 Low-dose penicillin was administered either to the mother before birth and then to mouse pups until weaning, or they were administered to pups after weaning. In both cases, alterations in gut bacterial balance occurred, but they fully recovered after antibiotics were stopped. On the other hand, metabolic changes occurred that persisted into adulthood. Increased growth, which included lean mass, fat mass, bone mass, or a combination were induced by the antibiotic exposure. In addition, decreases were found in four main bacteria: Lactobacillus, Allobaculum, Rikenellaceae, and Candidatus arthromitus. Finally, a decrease in intestinal immune responses and impaired intestinal barrier function were found, which may help explain how bacteria might trigger metabolic dysfunction.
To confirm that these metabolic effects were the result of microbial alterations, the researchers transplanted feces from the obese mice into germ-free mice who inherited the altered gut microbes and went on to gain fat mass in a similar manner. They proposed the term microbe-induced obesity (MIO) as a condition of increased fat accumulation that results from alterations in gut bacteria. This study suggests that losses of the four bacteria are detrimental when they occur (Lactobacillus, Allobaculum, Rikenellaceae, and Candidatus) during the critical developmental period of early infancy.
“These four organisms have either metabolic and/or immunologic interactions, which may contribute to the observed protection from weight gain in the control animals,” noted the researchers.
“This highlights a need for judicious use of antibiotics in clinical practice in early life,” noted Martin Blaser, MD, lead researcher and author of the eye-opening book Missing Microbes. Brenda and I discuss some of his research in our new book, The Skinny Gut Diet.
Microbe-induced obesity in conjunction with diet-induced obesity (because the two go hand in hand as we discuss in our book) are a sure set up for difficult-to-lose weight gain. This was confirmed by feeding a high-fat diet to the mice given low-dose penicillin, in which they found an amplified increase in fat mass. The researchers suggest that restoration of lost microbes after antibiotic use during infancy as a potential strategy to reverse MIO and its related effects.
It is clear to me that pre- and probiotics during pregnancy will prove to be a major way to ensure that the immune system and intestinal lining of the fetus will optimally develop, which may negate the need for antibiotics, for the most part. In the event that there is a need for antibiotics, I think it will soon become standard of care to place everyone who is taking antibiotics on probiotics to maintain microbiome stability. Probiotics can provide high colony count numbers with increased species of commensal bacteria to block the emergence and dominance of pathogenic bacteria that can spell disaster.
Further studies are needed to confirm these effects in humans, and to determine what species are key to the prevention of weight gain in later life.
- Ajslev TA, Andersen CS, Gamborg M, et al., “Childhood overweight after establishment of the gut microbiota: the role of delivery mode, pre-pregnancy weight and early administration of antibiotics.” Int J Obes (Lond). 2011 Apr;35(4):522–9.
- Murphy R, Stewart AW, Braithwaite I, et al., “Antibiotic treatment during infancy and increased body mass index in boys: an international cross-sectional study.” Int J Obes (Lond). 2014 Aug;38(8):1115–9.
- Trasande L, Blustein J, Liu M, et al., “Infant antibiotic exposures and early-life body mass.” Int J Obes (Lond). Jan 2013; 37(1): 16–23.
- Cho I, Yamanishi S, Cox L, et al., “Antibiotics in early life alter the murine colonic microbiome and adiposity.” Nature. 2012 Aug 30;488(7413):621–6.
- Cox LM, Yamanishi S, Sohn J, et al., “Altering the intestinal microbiota during a critical developmental window has lasting metabolic consequences.” Cell. 2014 Aug 14;158(4):705–21.
One out of every three adults has high blood pressure (hypertension), yet only about half of them have their blood pressure under control. Another one out of three adults has prehypertension, which means that they are on their well on their way to joining the first group. With two-thirds of American adults suffering from hypertension or prehypertension, the search is on for effective ways to lower blood pressure.
A recent systematic review and meta-analysis published in the American Medical Association journal Hypertension found that probiotics are an effective means of lowering blood pressure. The researchers analyzed nine studies that included 543 participants and found that probiotic consumption lowered systolic blood pressure by 3.56 and diastolic blood pressure by 2.38 mm Hg when compared to those adults who did not take probiotics.
The blood pressure lowering effects were even stronger in people taking higher doses of probiotics and when they were taken for a period of at least eight weeks. They also found greater effect from consuming multiple rather than single strains of probiotics. These findings suggest that taking a high-dose, multi-strain probiotic for a longer duration is more effective at lowering blood pressure.
“We believe probiotics might help lower blood pressure by having other positive effects on health, including improving total cholesterol and low-density lipoprotein, or LDL, cholesterol; reducing blood glucose and insulin resistance; and by helping to regulate the hormone system that regulates blood pressure and fluid balance,” stated Jing Sun, PhD, lead researcher.
The reduction of blood pressure in this analysis, although modest, is similar to that found in another analysis of salt reduction of 2,000 mg daily. Even modest blood pressure reductions are beneficial, however, and have been associated with a 22 percent reduced risk of cardiovascular death, heart attack, or stroke.
The benefits of probiotics for conditions outside the gut are growing at a rapid pace. This new analysis is excellent evidence that what happens in your gut affects the rest of your body. Keep taking your probiotics.
On average, children in the United States develop six respiratory tract infections each year. Another infection—gastroenteritis, also known as the stomach flu—accounts for over 1.5 million outpatients visits, 200,000 hospital visits, and about 300 deaths each year. Together, these infections account for a considerable degree of illness in children. If you are a parent, you are familiar with the frequency of these conditions during childhood.
The search continues for therapies that will reduce these childhood infections. A recent review published in the journal Nutrition Reviews highlights a potential answer for children under two.
The authors conclude that the evidence “suggests that preventive use of prebiotics decreases the rate of infections requiring antibiotic therapy in infants and children aged 0–24 months.”
Prebiotics are non-digestible fibers that promote the growth of beneficial bacteria in the intestines.
The researchers also state that prebiotics may be an effective preventive treatment for decreasing the rate of overall infections in these children. The prebiotics used in the studies include oligosaccharides, galacto-oligosaccharides (GOS), fructo-oligosaccharides (FOS), fructans, inulin, and oligofrutose.
Interestingly, the researchers were unable to find studies using prebiotics to prevent infections in children over the age of two. They suggest such studies be undertaken, since older children are commonly introduced to new environments in which they are exposed to acute infections.
I recently blogged about a meta-analysis that found beneficial effects of probiotics for the treatment and prevention of cold and flu in children. Together, these two papers give us strong evidence that gut microbes have a major effect on our children’s immune health both in and out of the digestive system.
When taken together, probiotics and prebiotics pack a powerful punch. There is a synergistic effect between the two. Fortunately, you can eat foods high in the prebiotic inulin. Chicory root, Jerusalem artichoke, leeks, onions, garlic, and bananas all contain high amounts. A probiotic supplement plus prebiotic foods is a great combination to help maintain a healthy balance bacteria in your gut.
Until recently, it was thought that the bladder—and therefore urine—is sterile, meaning that, in a healthy state, no bacteria live there. But a new study presented by researchers at the General Meeting of the American Society for Microbiology is changing how scientists view the urinary system.
Using an expanded culture technique able to detect bacteria that standard techniques do not, they found that urine from healthy women does, in fact, contain bacteria.
“Doctors have been trained to believe that urine is germ-free,” noted Linda Brubaker, MD, MS, one of the researchers. “These findings challenge that notion, so this research opens the door to exciting new possibilities for patient treatment.”
They found that the bacteria in urine of women with an overactive bladder (OAB) differs from that of healthy women.
“The presence of certain bacteria in women with overactive bladder may contribute to OAB symptoms,” noted lead investigator, Evann Hilt.
Could changing the balance of bacteria in the urinary system improve symptoms of overactive bladder? Scientists will next look at which bacteria are helpful and which are harmful, and whether certain bacteria trigger the development of overactive bladder as well as other urinary tract conditions. With this information, they will better be able to treat this condition. They may find that by altering the bacteria in the urinary system, they can improve symptoms of overactive bladder. There may one day be a probiotic specifically for this condition. I am sure there are many women out there crossing their legs and nodding, yes!
The results of this study are not surprising to me, since I have known for a while that probiotics can have a positive effect on urinary health. The mechanism of this benefit is not fully understood, but it seems to me that it must involve communication between bacteria within the urinary system. I will be interested to see how this research unfolds as scientists further explore the human microbiome. My hunch is that they will find bacteria in more areas of the body they previously thought did not contain microbes.
Malnutrition (severe or moderate acute malnutrition) affects 23 percent of children in developing countries.1 The World Health Organization estimates that malnutrition is the cause of one-third of all child deaths.2 Malnutrition, or inadequate nutrition, manifests most noticeably as delayed growth, but also includes deficiencies in vitamins, minerals, essential fatty acids, and protein.
A recently developed intervention for severe acute malnutrition, known as Ready-to-use Therapeutic Food, is currently being distributed to hundreds of thousands of children in the developing world. Other food interventions, such as a lentil and rice dish called khichuri-halwa, are being utilized. A recent study published in the journal Nature sought to understand whether the development of gut bacteria during infancy was associated with improvements in malnutrition after such interventions in Bangladeshi children.3
The researchers first tested the stool of healthy Bangladeshi children on a monthly basis during the first two years of life to determine the healthy development of gut bacteria. That is, they used these findings as a benchmark of a normally maturing gut bacterial community. After all, the first two to three years of life see some of the biggest changes in gut bacterial composition, and by this age, the gut microbes resemble that of an adult.
Next, they tested the gut bacteria of children with severe and moderate acute malnutrition before, during, and after receiving either the Therapeutic Food or the lentil and rice dish. Before the interventions, gut bacteria was found to be immature—that is, the gut microbes were found were not fully developed as they were in healthy children. After the food interventions, the children’s gut microbiota immaturity was only partially improved—and temporarily, at that. By four months after the interventions had ceased, their gut microbes reverted back to their original, immature state.
The researchers suggest that either a longer food intervention or a different food that more resembles the children’s native diet is needed. They also recommend “next-generation probiotics using gut-derived taxa [groups],” which I believe will have the best impact. What if they isolated the gut microbes from the healthy children and gave them to the malnourished children? Those microbes would take up residence in the children’s guts, especially if the children were also given a food that those bacteria naturally thrive on.
Aside from lack of food, gastrointestinal (GI) infection is another cause of malnutrition. During a GI infection, the immune system is taxed in such a way that a broad range of nutrients are required to fight the pathogenic organism. Let’s not forget that a healthy gut microbiota can help ward off such infections in the first place—and can help improve the body’s nutrient capacity. You see, gut microbes play an important role in the harvest of nutrients from food. They help to break down food so that the body can efficiently absorb the nutrients it needs. When the community of gut microbes is not a healthy one, the ability to absorb nutrients adequately is compromised. When this occurs during infancy along with a lack of food or an infection, malnutrition can be worsened.
I cannot overemphasize the importance of developing a healthy gut balance during infancy. Avoiding medically unnecessary Cesarean sections and antibiotics during pregnancy (and during infancy for baby), breastfeeding for at least one year (more is better), and taking probiotics during and after pregnancy along with eating fermented foods is the best way to set infants up with a healthy balance of gut microbes, both in developing countries and here at home.
1. Lazzerini M, Rubert L, and Pani P, “Specially formulated foods for treating children with moderate acute malnutrition in low- and middle-income countries.” Cochrane Database Syst Rev. 2013 Jun 21;6:CD009584.
2. http://www.who.int/maternal_child_adolescent/topics/child/malnutrition/en/ Accessed 6/19/2014.
3. Subramanian A, Huq S, Yatsunenko T, et al., “Persistent gut microbiota immaturity in malnourished Bangladeshi children.” Nature. 2014 Jun 4.
Probiotics, or beneficial bacteria, have been studied for a number of health conditions, but one of the most exciting benefits of probiotics is their effect on the common cold. A number of studies have looked at probiotic treatment and prevention of upper respiratory tract infections (cold and flu, most notably). A recent systematic review evaluated data from twelve randomized, controlled trials in children and adults and found that those people who had taken Lactobacillus and Bifidobacterium probiotics experienced fewer days of illness, shorter illness episodes, and fewer days absent from daycare, school, or work when compared to those participants who took a placebo.
“This paper shows that with the addition of live lactobacilli and bifidobacteria to your diet, the duration of upper respiratory tract infections (e.g. colds) could be shortened,” stated Sarah King, PhD. “Combined with results from a 2011 meta-analysis published in the Cochrane Database of Systematic Reviews, which demonstrated that probiotics can reduce the incidence of upper respiratory tract infections, the implications of these findings are significant and could translate into cost savings and quality of life improvements.” The economic impact of colds is estimated to cost the United States $40 billion each year, so any reduction in the common cold is welcome.
Probiotics impact the immune system in a number of ways. Up to 80 percent of the immune system resides in the gut. The gut bacteria help to educate the immune system so that it responds appropriately. So it’s no wonder that probiotics have a beneficial effect on the respiratory tract.
Clinical studies continue to link chronic, low-grade inflammation—also known as silent inflammation—with a growing number of health conditions and diseases. Because it can be present without being felt, this type of inflammation is particularly dangerous and can be harmful to the body over time.
Recently, a team of scientists from Texas A&M University found a link between our internal “body clocks” and the inflammatory response tied to metabolic disorders such as obesity and diabetes. It has to do with immune cells called macrophages, which control inflammatory response. Study results involving mice showed that a high-fat diet and irregular sleep disrupts the natural rhythms of our cells and tissues, which in turn triggers inflammation, fat accumulation, and ultimately insulin resistance—creating a vicious cycle.
“To promote human health, we need not only to eat healthy foods, but also more importantly to keep a healthy lifestyle, which includes avoiding sleeping late and eating at night,” said Dr. David Earnest, Texas A&M professor and one of the study’s lead authors. Here are four simple ways you can change your diet to help reduce the risk of inflammation and metabolic disorders:
- Partner with Probiotics: In clinical studies, daily supplementation with a high-potency probiotic has been shown to support the healthy function of white blood cells and help reduce the risk of inflammation-associated metabolic disorders.‡
- Add More Omega-3s: The Omega-3s that come from fish oil—specifically EPA and DHA—are particularly good at helping to prevent silent inflammation, in part by helping to balance out the inflammatory effects of the Omega-6 fats found in high amounts in the Standard American Diet (SAD).‡
- Don’t Forget the Fiber: If you aren’t eating enough fiber, the good bacteria in your gut may not be able to produce enough protective short-chain fatty acids.‡ This can lead to inflammation as the immune system responds inappropriately to healthy gut microbes and treats them as harmful bacteria. Aim for at least 35 grams of fiber daily.
- Load up on Antioxidants: Antioxidant-rich fruits and vegetables target free radicals in the body, which can damage cells and tissues and trigger inflammation. Opt for low-sugar fruits such as blueberries, raspberries, pomegranates, plums and cherries, along with non-starchy veggies such as kale, spinach, broccoli and Brussels sprouts. Olive oil, raw nuts and nut butters are also a good source of antioxidants.
In case you missed it, a recent episode of the Hallmark Channel daytime talk show Home & Family featured a topic I’m pretty passionate about… probiotics! Hosts Mark Steines and Cristina Ferrare talked to renowned nutrition specialist Dr. Melina Jampolis, who shared with viewers some important facts about probiotics—including what to look for in an effective probiotic supplement.
Her advice to viewers included adding more probiotic foods and supplements to the daily diet to help maintain digestive balance and promote immune health, and during the segment she pointed out that Ultimate Flora probiotics from ReNew Life are an excellent choice when it comes to selecting a high-potency probiotic supplement because they meet key criteria: high culture count, multiple strains of bacteria, delayed release capsules and guaranteed potency.
The episode called attention to the fact that there are literally trillions of bacteria in the human digestive tract (roughly ten times more than human cells) and how a shift in the balance of good (and neutral) to harmful bacteria in the gut can have a significant impact on our digestive health as well as the health of the whole body—something I talk about at length in my book and PBS show The Heart of Perfect Health.
Be sure to tune in if you missed it!
In some parts of the country (especially here in Florida where I live) allergy season is in full swing. So many people are suffering with congested sinuses, stuffy noses, and feeling like, well, not so great. Over 11 million people in the United States are diagnosed with allergic rhinitis, or hay fever—what most people simply call allergies—each year. I am sure there are many more people who do not get officially diagnosed, adding to this staggering number.
A recent study published in the European Journal of Clinical Nutrition found that people taking the probiotic Lactobacillus paracasei daily for five weeks in addition to their usual allergy medication had improved quality of life along with improved ocular symptoms (less watery, itchy, red, and swollen eyes). Improvement in specific nasal symptoms was not found, however.
“Probiotic foods or food supplements seem to be popular and widely used by subjects suffering from allergic rhinitis, however, a study under real-life conditions and in subjects receiving a medicinal treatment was needed,” noted the researchers. While they did find a benefit of the probiotic, more studies will be needed to determine whether the addition of other strains will increase the effect.
A number of probiotic strains have already been studied in people with allergic rhinitis, but most of them have been single strain studies with mixed results. Researchers have begun to look at multiple strain formulas for allergies, but we are still in the early stages of research. My hunch is that the multi-strain probiotic formulas will be more effective because they target a wider range of immune functions. I will keep you posted as I learn more.