Happy Thanksgiving to all our North American readers! Yes, despite this year being challenging in so many ways, it is a great time to take stock of the things that were good in our lives, even if they were occasioned by a whole slew of viral chaos. Perhaps we got to turn neighbor into friends, take up a new Zoom activity, finally fixed that leaky faucet, or perhaps we adopted a pandemic pooch for company in these times of isolation. And if you are indeed the guardian of a new canine best friend you might be wondering how much of the Thanksgiving celebration your pup can stomach. What foods are safe to offer and how much of the leftovers will you have to share with him or her? Although visits to veterinarians do rise during the holidays, dogs can share your some of Thanksgiving meal, like a little turkey and some sweet potatoes, but fatty foods, turkey bones, and desserts are firmly off the menu. And if your new charge overindulges during the holidays – and let’s face it, we all do – what can we do to ease their discomfort? Could the answer be in probiotics? Prebiotics?? Synbiotics??? What’s the difference anyway? Let’s take a look…
As 2020 turned from an unremarkable year to what feels like a decade of binge-watching TV on the couch while consuming our own weight in caramel corn, we’ve probably all noticed a certain new ‘tension’ on the waistband, a need to let the belt out another notch. So it’s understandable that we’re all seeking relief from the unfortunate – but arguably quite forgivable – results of our dietary excess. So we look to external solutions – in this case, health foods and nutritional supplements that offer probiotic or prebiotic benefits to ease that gastrointestinal distress. But what exactly are these comestibles and how do they work? Let’s start with some handy definitions.
In a nutshell, probiotics are live bacteria that work to support the microbiota of the gut microbiome. According to an article published in the British Medical Journal (BMJ), the microbiome is defined as ‘the collective genomes of the micro-organisms in a particular environment’ with the microbiota being the collective community of those micro-organisms.(1) And it might surprise you to know that ‘[a]pproximately 100 trillion micro-organisms (most of them bacteria, but also viruses, fungi, and protozoa) exist in the human gastrointestinal tract.’(2)
The care and feeding of that number of micro-organisms might be an intimidating proposition were it not for probiotics – fermented foods like sauerkraut, tempeh, kombucha, natto, miso, and kimchi, along with dairy products such as some yoghurts. Considered ‘health foods,’ probiotics may improve digestion, alleviate depression, promote heart health and, by forming short-chain fatty acids (SCFA) which nourish cells lining the colon, reduce inflammation. Conversely, other goodies such as those high in sugar (hello, pecan pie) or rich in fat (we’re looking at you, turkey skin) up-end the balance of gut bacteria, allowing non-beneficial bacteria to thrive.
Another important ingredient in the maintenance of beneficial gut bacteria is perhaps less well known. ‘Prebiotics’ refers to a type of fiber found in fruits such as berries and bananas, vegetables like asparagus and dandelion greens, alliums such as onions, leeks, and garlic, and, of course legumes such as beans or peas. Like their probiotic counterparts, they form SCFAs such as butyric acid which ‘provides your colon cells with about 70 percent of their total energy needs.’(3) Moreover, diets rich in or supplemented with butyric acid – also known as butyrate and butanoic acid – may help treat Irritable Bowel Syndrome (IBS), Crohn’s Disease, and colon cancer. Additionally studies in animal models have demonstrated that increased consumption of prebiotic foods can improve insulin sensitivity, thereby decreasing the risk of obesity. Hypothetically, if similar effects are observed in human trials, the future treatment of both obesity and type 2 diabetes may be impacted.
The bottom line: consumption of probiotics, prebiotics, and synbiotics (foods or supplements offering a synthesis of the two) is generally considered to bring an overall net positive to our diets.
If by now your head isn’t already spinning from the discussion (or maybe that extra glass of wine at Thanksgiving dinner?), there’s an additional term to consider: ‘postbiotics.’ And for pet guardians, the term is of particular significance. Why? According to an article in Petfood Industry, postbiotics potentially represent the new frontier in functional pet food. And while that’s a bold assertion, a clear explanation of the concept is somewhat elusive. Here’s one definition: ‘soluble factors (products or metabolic byproducts), secreted by live bacteria or released after bacterial lysis, such as enzymes, peptides, teichoic acids, peptidoglycan-derived uropeptides, polysaccharides, cell surface proteins and organic acids.’ And here’s another: ‘functional bioactive compounds, generated in a matrix during fermentation, which may be used to promote health. The term postbiotics can be regarded as an umbrella term for all synonyms and related terms of these microbial fermentation components.’ Making it a hat trick, here’s a third: ‘metabolites [that] are the new frontier in microbiome science. Scientists are learning that postbiotic metabolites are the master health-regulating compounds in the body. Your probiotic bacteria produce postbiotic metabolites, which are the tools that make up your ‘tool kit’ for good health. People who have a wider range of tools in their microbiome tool kit have a more effective tool kit, which does a better job regulating health throughout the body.’(4)
Confused? You’re not alone. As the article’s author, Debbie Phillips-Donaldson, notes: ‘even peer-reviewed articles published in the last two years still set out to establish and define postbiotics – that’s how new the concept is.’(6) Generally, however, the consensus is that postbiotics are propitious. Kerry, a company that brings a ‘deep knowledge of culture, life stages and related nutritional needs together with […] expertise in the multi-dimensional science of taste,’ characterizes them as ‘an exciting area around gut health because they can potentially provide similar beneficial effects as probiotics but without the survivability hurdles that living microorganisms can present.’(7)
And for pet food manufacturers the ‘survivability’ challenge is significant as the live bacteria struggle to outlast not only commercial processing, but also the stresses of transportation, extended shelf-life, and the rigors of the canine digestive system.
And not all probiotics are created equal. For spore-forming types such as Bacillus coagulans, the presence of a protective shell enables a generally successful journey to the gut where it can establish colony-forming units (CFUs) and work its magic. Unprotected strains such as Bifidobacterium or Lactobacillus, however, which are derived from lactic acid bacteria are unlikely to make it even as far as the microbiome, succumbing easily to the triple threat of light, heat, and stomach acid. So although, as Erik Bauer, Senior Technical Services Manager for Kerry’s ProActive Health division, notes, probiotics are the ‘preferred choice to help support pet digestive health because they are widely used and accepted by consumers in their own foods and beverages,’ they are not always the best choice.(8)
Hence the current interest and excitement around postbiotics.
According to Cynthia Rasmussen, a Business Development Manager at Kerry, the use of postbiotics effectively addresses the challenges of product exposure to heat and light, the requirement for a prolonged shelf-life, the use of elevated levels of salt in product recipes, and a generally inhospitable canine GI environment. Moreover, Rasmussen predicts an increased potential for product customization to benefit both an already ‘healthy digestive system during periods of stress or help older pets maintain optimal nutrient absorption as they age.’(9) All of which sounds like good news for canines increasingly stressed, we assume, by their guardian’s unremitting pandemic-induced proximity.
And what of those perpetually-present guardians themselves? Is this an area in which pet food manufacturers are leading the way for innovation within the human nutrition sector? Perhaps so if industry behemoth Cargill is any indication of trends. In an article appearing in Food Navigator this month, Cargill is reportedly engaged in ‘advanced conversations with CPG brands about using EpiCor – a ‘postbiotic’ ingredient claimed to have immune, digestive, and respiratory health benefits – in a range of applications.’(10) EpiCor is derived from ‘baker’s yeast [and] through the natural fermentation process new compounds are created such as beneficial beta glucans. EpiCor is comprised of proteins, fibers, vitamins, beta glucans among other ingredients with many benefits to help support a strong immune system.’(11) Contending that it is Generally Recognized As Safe (GRAS), Cargill anticipates receiving a ‘no objections’ letter from the Food and Drug Administration (FDA), allowing the company to add the substance to products as diverse as soups, cookies, and meal replacements. It will be interesting to see how far the use of the ‘umami-tasting ingredient’ will extend.
But as exciting as this innovation sounds, there is – of course – a dark twist to the pre-/pro-/syn-/postbiotic story that we’re sure you saw coming: product recalls.
According to ConsumerLab, in April of this year manufacturer GSK Consumer Healthcare was forced to recall ‘one lot of Benefiber Healthy Shape Prebiotic Fiber Supplement powder and four lots of Benefiber Prebiotic Fiber Supplement powder [due to their] potential to be contaminated with green plastic pieces or shavings from bottle caps.’(12)
The inclusion of foreign objects is bad enough but unfortunately it doesn’t end there. A group of EcoHealth Inc’s florAlign Prebiotic Formula products, for example, found itself subject to FDA recall due to pathogen contamination – in that case, Salmonella. As longtime readers will already be aware from oour previous articles, the symptoms of salmonellosis include fever, nausea, and abdominal pain and, if pathogens enter the bloodstream, can result in arthritis, aneurysms, and endocarditis. Given that it tends to be common among infants and children and those with already compromised immune systems, such as seniors, infection by the bacterium is a risk not to be taken lightly. Fortunately no cases of the condition were ultimately linked to the tainted product and, hopefully, lessons were learned.
Tragically this was not the case, however, with ABC Dophilus® Powder, a probiotic manufactured by Solgar Inc. of Leonia, NJ. The product was found to be contaminated with Rhizopus oryzae, a fungus that can cause mucormycosis, an infection that attacks the sinuses, lungs, or brain. Significantly, according to Forbes, ABC Dophilus® Powder is a ‘probiotic dietary supplement marketed specifically for use in infants and children,’ the very demographic most susceptible to this type of infection.(13) Furthermore, the supplement was used ‘as part of the in-hospital course of treatment for a very preterm infant (≤32 week gestation) who suffered from multiple complications, including intestinal mucormycosis. The eventual death of the very preterm infant […] prompted a review of the infant’s course of treatment [and another review] by the FDA and CDC.’(14)
The Forbes article notes that the ‘contaminating fungus is normally found in decaying organic matter like leaves or rotting wood,’ which does prompt the question of how rotting organics could have been introduced into a nutritional product for infants.(15) At the time of recall, Solgar Inc., then a part of Wyeth Consumer Products, struggled to offer an explanation of the contamination’s source, citing confidentiality issues vis à vis a contract manufacturer. The case ultimately led to the American Gastroenterological Association (AGA) issuing a reminder that ‘are considered dietary supplements and are not FDA-regulated like drugs. They are not standardized, meaning they are made in different ways by different companies and have different additives. How well a probiotic works may differ from brand to brand and even from batch to batch within the same brand. Probiotics also vary tremendously in their cost, and cost does not necessarily reflect higher quality.’(16)
Sobering words from a tragic situation.
However, despite instances of contamination in the range of ‘biotic’ products, the case for the use of beneficial microbes and bacteria is nonetheless growing increasingly stronger.
And it’s not just about what we feed ourselves or our beloved canine friends. According to a paper published in the journal Frontiers in Microbiology by lead author Irina Spacova of the Laboratory of Applied Microbiology and Biotechnology at Belgium’s University of Antwerp, it’s also about harnessing ‘the power of beneficial microbes to ameliorate the impact of worldwide problems.’(17) At a time when heavy metal toxins may be present in crops from contaminated regions, Spacova et al cite a study demonstrating that a probiotic, Lacticaseibacillus rhamnosus GR-1, is efficient in sequestering lead and cadmium, preventing them from crossing the intestinal epithelium, the lining of the colon. Furthermore, a paper by Phillipe M. Rosado of the Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Brazil, examines the potential for inoculating coral reef structures with putatively beneficial microorganisms for corals (pBCMs) to lessen the impact of coral bleaching caused by climate change. In the paper published by the National Center for Biotechnology Information in April 2019, Rosado et al posited that the manipulation of a coral’s microbiome could ‘lessen the effect of bleaching, thus helping to alleviate pathogen and temperature stresses, with the addition of BMCs representing a promising novel approach for minimizing coral mortality in the face of increasing environmental impacts.’(18)
Given that Australia’s Great Barrier Reef has, since 1995, lost an estimated 50% of its corals due to the climate change-driven increase in water temperature, microbial mitigation of the kind suggested by Rosado could halt the on-going degradation and promote eventual healing of the reef. And at this time of thanksgiving, in a year that has – for so many – seen neither cause for gratitude nor healing, an environmental benefit of this global scale is without doubt one innovation to be thankful for.
Are you excited at the potential for using beneficial bacteria to heal not only the GI tract but also the environment? Or are you a microbe-skeptic? Let us know your thoughts!