1Assistant Professor Tagore Institute Of Pharmacy And Research Sakri Bilaspur-495001
2Deparment Of Pharmacology, Gayatri College Of Pharmacy, Sambalpur
The gut microbiome, an intricate microbial ecosystem residing within the human gastrointestinal tract, has captivated scientific inquiry. Previously believed to outnumber human cells by a factor of ten, recent estimates paint a more balanced picture, suggesting a near one-to-one ratio between human and microbial constituents. This revelation positions us as remarkable hybrids, half-human and half-microbe. This paper delves into the multifaceted landscape of the gut microbiome, emphasizing its diverse composition and adaptability in response to dietary influences. Additionally, it scrutinizes the roles of prebiotics and probiotics in shaping this microbial milieu. Furthermore, the paper raises pertinent concerns regarding the quality and efficacy of commercial probiotic products, underscoring the need for stringent regulation and quality control. In essence, this paper explores the evolving narrative of the gut microbiome, emphasizing the intricate interplay between diet, microbial composition, and overall health.
The gut microbiome, our body's bustling microbial metropolis, has long been a source of fascination and amazement. Initially, it was believed that these tiny microbial citizens outnumbered our own human cells by a factor of ten. However, modern estimates have tipped the balance slightly, suggesting that we might be more of a 50-50 collaboration between human and microbe. Yes, you read that right – we're essentially half microbe! Now, let's take a stroll through this microbial cityscape. The gut microbiome, like any thriving metropolis, has its own hierarchy. At the top of the bacterial food chain, you'll find the Bacteroidetes and Firmicutes, the reigning monarchs of the microbial world. There are also smaller factions like the Proteobacteria, Verrucomicrobia, Actinobacteria, and Fusobacteria, each with its own unique role in this bustling community. But what's fascinating is that there's no one-size-fits-all when it comes to a "healthy" microbiome. It's like having a diverse and ever-changing population in a city – what works for one doesn't necessarily work for another.
Now, let's talk about food – the lifeblood of any city, including our gut microbiome's city. The gastrointestinal tract, our microbiome's neighbourhood, sees a constant influx of food and drink. Unsurprisingly, what we consume has a profound impact on this microbial community. For instance, those who dine on a diet rich in fiber tend to host a larger population of Prevotella, one of the friendly residents. On the flip side, folks indulging in diets high in protein and fat tend to be a hotspot for Bacteroides, another key microbial clique within the Bacteroidetes group. Here's where it gets even more intriguing: our microbiome is remarkably adaptable. Studies have shown that even a single day of dietary extremes, like going full carnivore or embracing a plant-based diet, can spark a revolution in our microbial landscape. However, our resilient microbiome often bounces back to its familiar composition once our diets return to their usual routines. But wait, there are two superheroes in our dietary story – probiotics and prebiotics! These dynamic duos wield special powers in shaping our microbiome. Probiotics are like the friendly tourists who drop in to spice up the microbial diversity, while prebiotics are the local gourmet chefs, whipping up delicious meals to keep our microbial residents happy. In the grand narrative of our gut microbiome, we're not just mere hosts; we're the city planners, curators, and residents, all playing a role in this ever-evolving microbial saga. It's a testament to the intricate balance between our diet, lifestyle, and these microscopic companions that make us a truly captivating half-human, half-microbe marvel.
Prebiotics
Prebiotics are like special treats for the helpful microorganisms living in our gut. These compounds, found in various foods, stimulate the growth and activity of beneficial bacteria and fungi, making them an essential part of our diet. Imagine them as the "food source" for our gut microbes. You can naturally find prebiotics in vegetables, fruits, whole grains, and legumes like peas and beans. Some packaged foods also contain ingredients classified as prebiotics, such as inulin and oligosaccharides. To be considered prebiotics, these compounds must meet specific criteria: they must resist digestion in the stomach and upper gastrointestinal tract, be selectively fermented by gut microorganisms, and promote the growth and activity of beneficial bacteria. The primary mechanism of action for prebiotics is fermentation. Bifidobacteria and Lactobacillus, two essential bacterial populations in our gut, utilize saccharolytic metabolism to break down these substrates. When these beneficial bacteria metabolize prebiotics, they produce short-chain fatty acids like butyrate, acetate, and propionate. These fatty acids have various health benefits, such as nourishing the gut lining cells, reducing the risk of certain cancers (like colorectal cancer), enhancing calcium absorption, and helping with constipation and diarrhoea. Moreover, they can enter the bloodstream and communicate with the brain, regulate the immune system, and control inflammation, benefiting our overall health. A diet rich in plant-based or high-fiber foods encourages the growth of bacteria with a greater capacity to ferment prebiotic fiber, leading to increased short-chain fatty acid production and promoting better health. You can find prebiotics in a variety of fruits, vegetables, and whole grains like apples, asparagus, bananas, oats, and more. These foods contain compounds like Galactooligosaccharides, Fructooligosaccharides, and Inulin, which act as prebiotics. Prebiotics are also available in dietary supplements, and babies can get them from their mother's milk. Apart from nourishing good gut bacteria, prebiotics offer other health benefits, including aiding in calcium absorption, regulating blood sugar spikes, speeding up food fermentation in the digestive system (reducing the risk of constipation), and keeping the gut cell lining healthy. Researchers are also investigating their potential role in managing gut diseases like irritable bowel syndrome and their connection to obesity. While prebiotics have many advantages, it's important not to overconsume them, as this can lead to gas or bloating. For most people, aiming for at least 5 grams of prebiotics in their daily diet is a good guideline. However, individuals with irritable bowel syndrome (IBS) should be cautious, as prebiotics can worsen their symptoms, potentially causing bloating, constipation, diarrhoea, or gas.
Probiotics
Probiotics are living microorganisms often touted for their potential health benefits, particularly in improving or restoring the balance of gut bacteria. While generally safe to consume, probiotics can occasionally lead to interactions with our body's natural flora, resulting in unwanted side effects. However, it's crucial to note that the scientific evidence supporting many of the health claims associated with probiotics is limited. The booming probiotics market has led to a demand for stricter scientific validation of the supposed benefits these microorganisms offer. Despite claims of reducing gastrointestinal discomfort, boosting immune health, alleviating constipation, or preventing common colds through consumer probiotic products, such assertions lack robust scientific backing. In fact, such claims are deemed deceptive advertising by the Federal Trade Commission in the United States. Researchers are also exploring the potential therapeutic value of probiotics in addressing various conditions, including stomach ulcers caused by H. pylori, infections (such as urinary tract, vaginal, gastrointestinal, sinus, and respiratory infections), dental issues, allergies, and liver diseases. However, more comprehensive research is required to determine the safety and efficacy of probiotics for these specific health concerns. In terms of their therapeutic benefits, probiotics offer a range of advantages for both humans and animals. These include reducing lactose intolerance symptoms, improving nutrient absorption, aiding in lactose digestion, regulating gut movement, and enhancing immune function. Probiotics can also help lower the risk of allergies, reduce inflammation in the gut, and combat harmful pathogens like E. coli and Staphylococcus aureus. Additionally, they contribute to increased nutritional absorption, better digestion, and improved vitamin and mineral uptake. Furthermore, probiotics assist in maintaining the health of the intestinal and urogenital flora, regulate gut motility (helping with issues like constipation and irritable bowel syndrome), and reduce the frequency and duration of diarrhoea caused by various factors, including antibiotics and infections. Probiotics play a role in maintaining the integrity of the gut lining, supporting the immune system, and even exhibiting anti-cancer, anti-mutagenic, and anti-allergic properties. They can enhance overall well-being, combat Candida infections, alleviate inflammatory digestive conditions like Inflammatory Bowel Disease (IBD), Crohn's disease, and Ulcerative Colitis, as well as provide relief from urinary tract infections. Probiotics create an unfavourable environment for harmful pathogens like E. coli, block their attachment sites, and can even inactivate their toxins. These beneficial microorganisms primarily colonize the intestinal tract and reinforce our body's defence mechanisms by stimulating mucosal immune responses. Studies suggest that lactic acid bacteria, such as Lactobacillus and Bifidobacterium, and their fermented products are effective in enhancing both innate and adaptive immunity, preventing gastric mucosal lesions, reducing allergies, and defending against intestinal pathogens.
Side effects
The intricate manipulation of the gut microbiota can give rise to intricate bacteria-host interactions.
While probiotics are generally regarded as safe, there are certain circumstances that raise concerns about their safety. Individuals with specific medical conditions, such as immunodeficiency, short bowel syndrome, central venous catheters, cardiac valve disease, and premature infants, may be at an elevated risk of experiencing adverse events associated with probiotic consumption. In individuals who are severely ill, particularly those suffering from inflammatory bowel disease, there exists a potential risk of viable bacteria from the gastrointestinal tract translocating to internal organs, a phenomenon known as bacterial translocation. This process can result in adverse health consequences, including bacteraemia, where bacteria enter the bloodstream, potentially leading to severe health issues. In rare cases, when probiotics are consumed by children with compromised immune system function or those who are already critically ill, it may result in bacteraemia or fungemia, where bacteria or fungi enter the bloodstream. This can escalate to sepsis, a life-threatening condition. While there have been suggestions that Lactobacillus species might contribute to obesity in humans, it's essential to note that no concrete evidence supporting this relationship has been discovered.
Food sources
Live probiotic cultures are part of fermented dairy products, other fermented foods, and probiotic-fortified foods. Additionally, lactic acid bacteria (LABs), which are food fermenting bacteria, have the ability to prevent food spoilage and can improve the nutritive value of the foods they inhabit. Also due to its low cost and low energy requirements when processing and preparing foods, acid fermentation combined with salting remains one of the most practical methods of preservation of fresh vegetables, cereal gruels, and milk-cereal mixtures.
Some commonly foods rich in probiotics are:
Probiotic supplement
In addition to incorporating probiotics into our diet through food, we have the option of using dietary supplements, which offer a wide range of probiotic strains and doses. It's important to note that these supplements are not classified as drugs, so they don't require approval from the Federal Drug Administration (FDA). Manufacturers can market these supplements with claims of safety and effectiveness. However, it's crucial to consult with a healthcare provider before making any significant changes to your diet or starting a new supplement regimen. Probiotic supplements come in various forms, making them accessible to different preferences and needs. These forms include foods, drinks, capsules or pills, powders, and liquids. Many of these products contain a mix of live microorganisms rather than just a single strain. Despite the availability of numerous commercial products labelled as "probiotics," it's essential to be cautious because not all of them have undergone rigorous research studies to support their claims. For those unfamiliar with probiotic research, it can be challenging to discern which products are backed by scientific evidence. To determine the potency of probiotics in supplements, they are measured in colony forming units (CFU), indicating the number of viable cells. You may see CFU amounts on product labels, such as 1 x 109 for 1 billion CFU or 1 x 1010 for 10 billion CFU. While many probiotic supplements contain between 1 to 10 billion CFU per dose, some products boast higher counts, even reaching up to 50 billion CFU or more. It's worth noting that higher CFU counts do not necessarily guarantee better health effects. In some cases, probiotic supplements are combined with prebiotics, which are complex carbohydrates that serve as a food source for the beneficial bacteria in your gut. Prebiotics, like inulin, pectin, and resistant starches, nourish and support the growth of these good bacteria, promoting a healthy gut environment. When a supplement combines both probiotics and prebiotics, it's referred to as a synbiotic. The market offers a variety of commercial probiotic products, reflecting the growing awareness of health and hygiene among consumers. However, despite their popularity, the quality control of these products remains a significant concern. Our study aims to evaluate some commonly available probiotic supplements using basic microbiological tools to ensure their effectiveness and safety for consumers
Evidence of Quality Control Issues Across Global Probiotic Markets
The concept of probiotics, introduced two decades ago, has sparked ongoing debates within the scientific community, shaping the landscape of gut health. Probiotics hold significant implications not only for researchers but also for regulatory bodies, the food industry, consumers, and healthcare professionals. In a study by Dioso et al. (2020), the quality of ten commercial probiotic products for children in the Philippines and South Korea came under scrutiny. This comprehensive analysis involved assessing viable bacterial counts and identifying the bacterial species within each product. Shockingly, one out of the ten products contained significantly fewer viable microorganisms than claimed on the label. Even more concerning, Enterococcus strains, undisclosed on the labels, were found in four products. Some of these strains produced biogenic amines and displayed resistance to antibiotics. Furthermore, metagenomic analyses unveiled that one product did not contain the majority of the microorganisms it claimed to have. This study shed light on the crucial need for rigorous quality control and regulation, especially for probiotics intended for vulnerable consumers like infants and young children. Similarly, Glowniak et al. (2019) conducted an assessment of ten commonly available commercial probiotic products in Poland. Their findings were eye-opening, as five of these products did not meet the declared viable bacterial counts. Additionally, not all the probiotic strains listed on the labels were detected during the analyses. These revelations underscore the urgent necessity for regular quality control measures to guarantee the promised health benefits of probiotics. Dodoo (2017) delved into the resilience of commercial probiotics against the harsh environment of gastric acid. Through gastrointestinal tolerance testing, they assessed three commercial probiotics and a freeze-dried Lactobacillus acidophilus strain. Surprisingly, all the commercial products contained the minimum number of probiotic strains indicated on their labels. However, when subjected to gastric acid tolerance tests, both commercial probiotics and the freeze-dried strain demonstrated substantial reductions in colony-forming units within just five minutes. Encapsulation for targeted delivery into the intestines resulted in improved viabilities, emphasizing the need to navigate the challenges of the stomach's acidity for probiotic effectiveness. Mansa Fredua-Agyeman et al. (2016) conducted a study examining the accuracy of label claims for commercially available probiotics in the UK. Their findings were illuminating, revealing that while all products contained viable probiotic bacteria, only a mere 43% of them met or exceeded the claimed culture concentration. Furthermore, none of the multi-species products contained all the labeled probiotic bacteria, and misidentification of some species was observed. This highlights the persisting quality issues in commercial probiotics, emphasizing the necessity for comprehensive legislation to ensure their quality and efficacy. Weese & Martin (2011) turned their attention to probiotics for animals, evaluating labels and bacterial contents of 25 commercial probiotics marketed for veterinary use. Their findings were equally concerning, with deficiencies in product labels and discrepancies between label claims and actual bacterial contents. This underscores the importance of vigilant scrutiny and the demand for evidence of quality control in the veterinary probiotic market.
DISCUSSION
In recent years, there has been a growing appreciation for the significance of the gut microbiome, a vast community of microorganisms residing in our gastrointestinal tract. This microbiome, once thought to outnumber human cells by a factor of ten, is now considered to have a nearly one-to-one ratio with human cells. This shift in understanding highlights the substantial influence these microbes have on our overall health, effectively making us slightly more microbe than human. The composition of the gut microbiome is diverse and highly individualized, with no universally agreed-upon definition of what constitutes a "healthy" microbiome. Diet plays a pivotal role in shaping this microbial landscape, with high-fiber diets favouring certain bacterial populations, while diets rich in protein and fat promote different groups. Remarkably, even short-term dietary alterations can cause significant shifts in the microbiome, although it tends to revert to its original state once regular eating patterns resume.
Prebiotics, non-digestible compounds found in specific foods, have emerged as key players in maintaining a healthy gut microbiome. They act as nourishment for beneficial gut bacteria, stimulating their growth and activity. On the other hand, probiotics, live microorganisms believed to offer health benefits when consumed, have gained popularity for their potential to improve digestive health and immunity. However, questions surrounding the effectiveness of probiotics persist, necessitating further research. A pressing concern in the realm of gut health is the quality and accuracy of commercial probiotic products. Studies have revealed discrepancies between label claims and the actual content and viability of probiotics in these products. Safety issues have also arisen, particularly among vulnerable populations. Consequently, there is a growing call for stricter regulation and quality control of probiotic products to ensure they deliver the promised health benefits.
In conclusion, this evolving field of gut health underscores the intricate relationship between diet, microbiome composition, and overall well-being. While prebiotics and probiotics show promise in maintaining gut health, more research is essential to unravel their full potential. Ensuring the quality and efficacy of commercial probiotic products remains a critical concern, especially as awareness of gut health continues to rise.
CONCLUSION
In summation, the gut microbiome, once thought to be a microbial dominion overshadowing our human cells, has emerged as a nearly equal partner in our biological narrative. Its diverse composition and responsiveness to dietary cues make it an enthralling subject of scientific exploration. Prebiotics and probiotics play pivotal roles in this narrative, shaping the microbiome's course. Nevertheless, questions loom regarding the efficacy and safety of commercial probiotic products, necessitating stringent quality control and regulation. As we conclude this research journey, the intricate interplay between diet, microbial composition, and overall health remains a compelling saga. We are not just masters of this topic; we are its chroniclers, and as science advances, the gut microbiome's tale continues to unravel, promising a future of profound insights.
REFERENCES
Akanksha Patel, Manmath Purohit, The Gut Microbiome, Dietary Influence, Probiotics, And Prebiotics: An Intricate Narrative, Int. J. of Pharm. Sci., 2024, Vol 2, Issue 3, 739-746. https://doi.org/10.5281/zenodo.10845598
10.5281/zenodo.10845598
