EFFECT OF SUPPLEMENTAL PREBIOTICS, PROBIOTICS, AND BIOACTIVE PROTEINS ON THE MICROBIOME COMPOSITION is a well-researched Life Sciences Thesis/Dissertation topic, it is to be used as a guide or framework for your Academic Research.
The composition and metabolic activity of the microbiome affect many aspects of health, and there is a current interest in dietary constituents that may affect this system. The purpose of this study was to evaluate the effects of a mix of probiotics, a mix of prebiotics, and a bioactive protein fraction on the microbiome when fed to mice individually and in combination. Mice were fed the total western diet (TWD) supplemented with prebiotics, probiotics, and Tri-Factor (bioactive proteins) individually and in combination for four weeks.
Subsequently, effects on the composition of the gut microbiome, gut short-chain fatty acids (SCFAs) concentration, gut inflammation, and integrity of the mucosal barrier were analyzed. Ruminococcus gnavus was increased in mice gut microbiome after feeding prebiotics. Bifidobacterium longum was increased after feeding probiotics. Probiotic was associated with higher level of Clos tritium neonatale. The treatments affected beta-diversity with exception of Tri-Factor, but not alpha diversity of microbiome.
All treatments were associated with lower plasma zonulin, compared to the control group, indicating an effect on gut permeability. There were no treatment effects on cecal or fecal SCFAs, and the treatments did not affect gut inflammation as measured by fecal calprotectin.
Prebiotics and probiotics are two common dietary supplements that have been shown to affect gut health in both rodent and human studies. Prebiotics are substrates that are utilized by select gut microorganisms, and which confer a health benefit (Gibson et al., 2017; Gibson, Probert, Van Loo, Rastall, & Roberfroid, 2004).
Probiotics are bacteria that improve gut health, and which come predominantly from the Lactobacillus and Bifidobacterium genera (Colin Hill et al., 2014; C. Hill et al., 2014; Mack, 2005). Most prebiotics are oligosaccharides, which pass undigested through the small intestine to the colon and are fermented by intestinal bacteria and stimulate the growth of specific microbial taxa (Blaut, 2002; Rastall, 2010; Roberfroid, 2007).
Probiotics are added as a culture of fermented foods like yogurt and kefir or naturally present as a starter on vegetables for kimchi and sauerkraut. They are also taken as supplements for humans. There have been many model rodent and human clinical studies that have investigated the health benefits of prebiotics, probiotics, and/or synbiotics (prebiotics and probiotics administered together).
Such health benefits include the promotion of gut fermentation, modulation of the microbiome composition, reduction of gut inflammation, decreased susceptibility to food allergy, and prevention of cancer (I. Cho & Blaser, 2012; Swennen, Courtin, & Delcour, 2006).
Suggested benefits of probiotics include improvement of the gut barrier function, increased competitive adherence to the mucosa and epithelium, gut microbiota modification, and regulation of the gut-associated lymphoid immune system (Saez-Lara, Robles-Sanchez, Ruiz-Ojeda, Plaza-Diaz, & Gil, 2016).
In mice, many studies have reported large increases in cecal and fecal SCFAs with prebiotic inclusion in the diet, which is likely due to the quantity. For example, mouse diets are often supplemented with 5-10% prebiotics (B. S. Hamilton et al., 2017; Murakami et al., 2015a; Nihei et al., 2018; Weitkunat et al., 2015a).
Hamilton et al fed 10% inulin or bovine milk oligosaccharides to mice on a high-fat diet (4500 kcal/kg) which increased cecal butyrate and propionate (B. S. Hamilton et al., 2017). We it Kuna supplemented a high-fat diet in mice with 10% inulin, and acetate, propionate, and butyrate were all increased in the cecum, as were total SCFAs (Nihei et al., 2018). Nice et al includes 5.5% cyclodextrin to a high-fat diet (~5250 kcal/kg) which was associated with an increase in all cecal SCFAs except n-valeric acid. Last, Murakami added 10% epilactose to both low and high-fat diets which increase all cecal SCFAs except lactic acid (Murakami et al., 2015b).
In the studies above, prebiotics was associated with impressive health benefits. For example, supplementation prevented adipose development (B. S. Hamilton et al., 2017; Nihei et al., 2018), gut permeability (M. K. Hamilton et al., 2017), improved lipid metabolism (Nihei et al., 2018; Weitkunat et al., 2015b), and increased energy expenditure (Murakami et al., 2015b; Nihei et al., 2018).
In human trials, prebiotics is typically supplemented between 5 and 20 g/d (Childs et al., 2014; Finegold et al., 2014; Holscher et al., 2015; Lecerf et al., 2012; Rajkumar et al., 2015; Vandeputte et al., 2017; Wilms et al., 2016). Fecal SCFAs have been measured in some studies, and to date, a clear effect has not been established.
No change in fecal SCFAs was determined after 1.4 or 2.8 g/d XOS for 8 weeks (Finegold et al., 2014), or 5 and 7.5 g/d inulin for 21d (Holscher et al., 2015). Conversely, consumption of 5g/d XOS for 4 weeks increased fecal butyrate and decreased acetate, while a mix of 3g/d inulin and 1g/d XOS resulted in an increase in propionate and total SCFAs (Lecerf et al., 2012).
Childs et al provided subjects with 8g/d XOS and 109 CFU Bifidobacterium animalis subspecies lactis Bi-07, singly and in combination for 21d (Childs et al., 2014). Individually, both treatments reduced fecal acetate and butyrate, but the combination did not. In addition, the combination increased fecal iso-valeric acid. At higher intakes, prebiotic supplementation has been shown to increase fecal SCFAs but is also associated with an increase in gastrointestinal stress. Clarke et al fed subjects either 3 × 5 g/d of a mixture of inulin and FOS or maltodextrin for 28d (Clarke et al., 2016).
The prebiotic supplementation significantly increased total fecal SCFAs but was associated with significant increases in self-reported GI symptoms and headaches. More concerning, however, is the fact that the 15g/d prebiotic supplementation increased circulating inflammatory cytokines, the proportion of immune cells that expressed TLR2 and TLR4, and the response to TLR2 agonists in an ex vivo assay.
The authors suggested that increases in these markers, while moderate, were consistent with increased immune cell contact with militerature on translating intakes of PREBIOTICS between rodents and humanscrobial stimuli.
Rodent studies suggest that substantial intakes of prebiotics may improve metabolic health, yet it is unclear if such levels can be achieved in human diets. To date, there has been little discussion in the. A 25 g mouse consuming 2.5 g of food a day with 10% prebiotics will ingest 0.25 g, or 10g/kg. For a 70 kg, that translates to 700g of PREBIOTICS per day.
However, if the nutrient density is used and the prebiotics are normalized to kcal, 2.5g of a high-fat diet (5000 kcal/g) with 10% prebiotics would deliver 20 mg/kcal. For a 2500 kcal diet, an equivalent intake would be 50g/d, which is significantly higher than the Institute of Medicine’s recommendation for total dietary fiber, which is 14g/1000 kcal The effects on gut microbiome were observed when administered only PROBIOTICS or combined with prebiotics.
The changes in the gut microbiome can contribute to an increased susceptibility to diseases both within and outside the gut (Cénit, Matzaraki, Tigchelaar, & Zhernakova, 2014).
There have been a number of studies that have shown a modification of gut microbiome when mice are supplemented with large doses of prebiotics, probiotics, individually or in combination (Carasi et al., 2015; W. Cheng et al., 2017; W Cheng et al., 2018; Cortez-Pinto et al., 2016; Delbes et al., 2018; Foure et al., 2018; Frece et al., 2009; Mariman, Tielen, Koning, & Nagelkerken, 2015; Nihei et al., 2018; Singh et al., 2017; Wang et al., 2012).
Changes are typically an increase in abundance of fecal Bifidobacteria, Lactobacilli, and Alloprevotella (W. Cheng et al., 2017; W Cheng et al., 2018; Delbes et al., 2018; Frece et al., 2009; M. K. Hamilton et al., 2017; Mischke et al., 2018; Nihei et al., 2018; Singh et al., 2017).
The Firmicutes / Bacteroidetes ratio has also been affected by treatments (Foure et al., 2018). An increased ratio of Firmicutes to Bacteroidetes was observed in obese versus lean subjects (Cénit etal., 2014; Turnbaugh et al., 2008).