Fate and effects of Camembert cheese micro-organisms in the human colonic microbiota of healthy volunteers after regular Camembert consumption

Effect of Consumption of Animal Products on the Gut Microbiome Composition and Gut Health

The gut microbiome is critical in human health, and various dietary factors influence its composition and function. Among these factors, animal products, such as meat, dairy, and eggs, represent crucial sources of essential nutrients for the gut microbiome. However, the correlation and characteristics of livestock consumption with the gut microbiome remain poorly understood. This review aimed to delineate the distinct effects of meat, dairy, and egg products on gut microbiome composition and function. Based on the previous reports, the impact of red meat, white meat, and processed meat consumption on the gut microbiome differs from that of milk, yogurt, cheese, or egg products. In particular, we have focused on animal-originated proteins, a significant nutrient in each livestock product, and revealed that the major proteins in each food elicit diverse effects on the gut microbiome. Collectively, this review highlights the need for further insights into the interactions and mechanisms underlying the impact of animal products on the gut microbiome. A deeper understanding of these interactions would be beneficial in elucidating the development of dietary interventions to prevent and treat diseases linked to the gut microbiome.

Gut microbiome and cancer implications: Potential opportunities for fermented foods

There is a critical opportunity to improve response to immunotherapies and overall cancer survivorship via dietary interventions targeted to modify the gut microbiome, and in turn, potentially enhance anti-cancer immunity. A promising dietary intervention is fermented foods, which may alter gut microbiome composition and, in turn, improve immunity. In this article, we summarize the state of the literature pertaining to the gut microbiome and response to immunotherapy and other cancer treatments, potential clinical implications of utilizing a fermented foods dietary approach to improve cancer treatment outcomes, and existing gaps in the literature regarding the implementation of fermented food interventions among individuals with cancer or with a history of cancer. This review synthesizes a compelling rationale across different disciplines to lay a roadmap for future fermented food dietary intervention research aimed at modulating the gut microbiome to reduce cancer burden.

Peptidomics Profile, Bioactive Peptides Identification and Biological Activities of Six Different Cheese Varieties

Several recent published studies reported that cheese consumption may protect against the onset of cardiovascular diseases and type-2 diabetes due to the presence of bioactive peptides. In the present work, six cheese varieties (the Egyptian traditional cheeses Karish, Domiati and Ras as well as Feta-type, Gouda and Edam cheeses) were characterized for their peptidomics profiles with high-resolution mass spectrometry, biological activities and content in bioactive peptides. The highest ACE-inhibitory and DPP-IV-inhibitory activities were found in Gouda cheese, which also displayed the highest antioxidant activity. A total of 809 peptides originating from the major milk proteins were identified, and 82 of them were bioactive. Most of them showed ACE-inhibitory, antioxidant and DPP-IV-inhibitory activities. The highest amount of the in vivo anti-hypertensive tripeptides VPP and IPP was found in Gouda cheese (39.19 ± 1.26 and 17.72 ± 0.89 mg/100 g of cheese, respectively), whereas the highest amount of APFPE was detected in Edam cheese (509.13 ± 20.44 mg/100 g of cheese). These results suggest that the intake of Edam, Domiati and, especially, Gouda cheeses may result in a possible anti-hypertensive effect in hypertensive subjects.

Fermented Foods, Health and the Gut Microbiome

Fermented foods have been a part of human diet for almost 10,000 years, and their level of diversity in the 21st century is substantial. The health benefits of fermented foods have been intensively investigated; identification of bioactive peptides and microbial metabolites in fermented foods that can positively affect human health has consolidated this interest. Each fermented food typically hosts a distinct population of microorganisms. Once ingested, nutrients and microorganisms from fermented foods may survive to interact with the gut microbiome, which can now be resolved at the species and strain level by metagenomics. Transient or long-term colonization of the gut by fermented food strains or impacts of fermented foods on indigenous gut microbes can therefore be determined. This review considers the primary food fermentation pathways and microorganisms involved, the potential health benefits, and the ability of these foodstuffs to impact the gut microbiome once ingested either through compounds produced during the fermentation process or through interactions with microorganisms from the fermented food that are capable of surviving in the gastro-intestinal transit. This review clearly shows that fermented foods can affect the gut microbiome in both the short and long term, and should be considered an important element of the human diet.

Effect of fermented foods on some neurological diseases, microbiota, behaviors: mini review

Fermented foods are among the traditional foods consumed for centuries. In recent years, awareness of fermented foods has been increasing due to their positive health benefits. Fermented foods contain beneficial microorganisms. Fermented foods, such as kefir, kimchi, sauerkraut, and yoghurt, contain Lactic acid bacteria (LAB), such as Lactobacilli, Bifidobacteria, and their primary metabolites (lactic acid). Although studies on the effect of consumption of fermented foods on diabetes, cardiovascular, obesity, gastrointestinal diseases on chronic diseases have been conducted, more studies are needed regarding the relationship between neurological diseases and microbiota. There are still unexplored mechanisms in the relationship between the brain and intestine. In this review, we answer how the consumption of fermented foods affects the brain and behavior of Alzheimer's disease, Parkinson's disease, multiple sclerosis disease, stroke, and gut microbiota.

Role of Exposure to Lactic Acid Bacteria from Foods of Animal Origin in Human Health

Animal products, in particular dairy and fermented products, are major natural sources of lactic acid bacteria (LAB). These are known for their antimicrobial properties, as well as for their roles in organoleptic changes, antioxidant activity, nutrient digestibility, the release of peptides and polysaccharides, amino acid decarboxylation, and biogenic amine production and degradation. Due to their antimicrobial properties, LAB are used in humans and in animals, with beneficial effects, as probiotics or in the treatment of a variety of diseases. In livestock production, LAB contribute to animal performance, health, and productivity. In the food industry, LAB are applied as bioprotective and biopreservation agents, contributing to improve food safety and quality. However, some studies have described resistance to relevant antibiotics in LAB, with the concomitant risks associated with the transfer of antibiotic resistance genes to foodborne pathogens and their potential dissemination throughout the food chain and the environment. Here, we summarize the application of LAB in livestock and animal products, as well as the health impact of LAB in animal food products. In general, the beneficial effects of LAB on the human food chain seem to outweigh the potential risks associated with their consumption as part of animal and human diets. However, further studies and continuous monitorization efforts are needed to ensure their safe application in animal products and in the control of pathogenic microorganisms, preventing the possible risks associated with antibiotic resistance and, thus, protecting public health.

Colonization Ability and Impact on Human Gut Microbiota of Foodborne Microbes From Traditional or Probiotic-Added Fermented Foods: A Systematic Review

A large subset of fermented foods act as vehicles of live environmental microbes, which often contribute food quality assets to the overall diet, such as health-associated microbial metabolites. Foodborne microorganisms also carry the potential to interact with the human gut microbiome via the food chain. However, scientific results describing the microbial flow connecting such different microbiomes as well as their impact on human health, are still fragmented. The aim of this systematic review is to provide a knowledge-base about the scientific literature addressing the connection between foodborne and gut microbiomes, as well as to identify gaps where more research is needed to clarify and map gut microorganisms originating from fermented foods, either traditional or added with probiotics, their possible impact on human gut microbiota composition and to which extent foodborne microbes might be able to colonize the gut environment. An additional aim was also to highlight experimental approaches and study designs which could be better standardized to improve comparative analysis of published datasets. Overall, the results presented in this systematic review suggest that a complex interplay between food and gut microbiota is indeed occurring, although the possible mechanisms for this interaction, as well as how it can impact human health, still remain a puzzling picture. Further research employing standardized and trans-disciplinary approaches aimed at understanding how fermented foods can be tailored to positively influence human gut microbiota and, in turn, host health, are therefore of pivotal importance.

Does Consumption of Fermented Foods Modify the Human Gut Microbiota?

The human microbiota is a key contributor to many aspects of human health and its composition is largely influenced by diet. There is a growing body of scientific evidence to suggest that gut dysbiosis (microbial imbalance of the intestine) is associated with inflammatory and immune-mediated diseases (e.g., inflammatory bowel disease and asthma). Regular consumption of fermented foods (e.g., kimchi, kefir, etc.) may represent a potential avenue to counter the proinflammatory effects of gut dysbiosis. However, an assessment of the available literature in this research area is lacking. Here we provide a critical review of current human intervention studies that analyzed the effect of fermented foods on the composition and/or function of the human gut microbiota. A total of 19 human intervention studies were identified that met this search criteria. In this review, we discuss evidence that consumption of fermented foods may modify the gut microbiota in humans. Further, there is cursory evidence to suggest that gut microbiota compositional changes mediate associations between fermented food consumption and human health outcomes. Although promising, there remains considerable heterogeneity in the human populations targeted in the intervention studies we identified. Larger longitudinal feeding studies with longer follow-up are necessary to confirm and enhance the current data. Further, future studies should consider analyzing microbiota function as a means to elucidate the mechanism linking fermented food consumption with human health. This review highlights methodologic considerations for intervention trials, emphasizing an expanse of research opportunities related to fermented food consumption in humans.

Cheese and Cardiovascular Disease Risk: A Review of the Evidence and Discussion of Possible Mechanisms

Currently, the effect of dairy products on cardiovascular risk is a topic much debated and with conflicting results. The purpose of this review is to give an overview of the existing literature regarding the effect of cheese intake and risk of cardiovascular disease (CVD). Studies included reporting the intake of cheese and risk of CVD or risk markers of CVD represent four human intervention studies, nine prospective studies, one prospective case-cohort study, one prospective nested case-control study, five case-control studies, five cross-sectional studies and three correlation studies. The possible mechanisms that may be of importance include calcium, protein, fermentation and the fatty acid composition of cheese. Results from four prospective studies reported no association between cheese intake and CVD risk, whereas one reported an increased risk, two reported a decreased risk and one reported no association in men but a decreased risk in women. In addition, results from four intervention studies indicated no harmful effect on cholesterol concentrations when comparing fat intake from cheese with fat from butter. The underlying mechanisms for these findings still need to be elucidated.

Repertory of eukaryotes (eukaryome) in the human gastrointestinal tract: taxonomy and detection methods

Eukaryotes are an important component of the human gut, and their relationship with the human host varies from parasitic to commensal. Understanding the diversity of human intestinal eukaryotes has important significance for human health. In the past few decades, most of the multitudes of techniques that are involved in the diagnosis of the eukaryotic population in the human intestinal tract were confined to pathological and parasitological aspects that mainly rely on traditionally based methods. However, development of culture-independent molecular techniques comprised of direct DNA extraction from faeces followed by sequencing, offer new opportunities to estimate the occurrence of eukaryotes in the human gut by providing data on the entire eukaryotic community, particularly not-yet-cultured or fastidious organisms. Further broad surveys of the eukaryotic communities in the gut based on high throughput tools such as next generation sequencing might lead to uncovering the real diversity of these ubiquitous organisms in the human intestinal tract and discovering the unrecognized roles of these eukaryotes in modulating the host immune system and inducing changes in host gut physiology and ecosystem.

Eukaryote culturomics of the gut reveals new species

The repertoire of microeukaryotes in the human gut has been poorly explored, mainly in individuals living in northern hemisphere countries. We further explored this repertoire using PCR-sequencing and culture in seven individuals living in four tropical countries. A total of 41 microeukaryotes including 38 different fungal species and three protists were detected. Four fungal species, Davidiella tassiana, Davidiella sp., Corticiaceae sp., and Penicillium sp., were uniquely detected by culture; 27 fungal species were uniquely detected using PCR-sequencing and Candida albicans, Candida glabrata, Trichosporon asahii, Clavispora lusitaniae, Debaryomyces hansenii, Malassezia restricta, and Malassezia sp. were detected using both molecular and culture methods. Fourteen microeukaryotes were shared by the seven individuals, whereas 27 species were found in only one individual, including 11 species in Amazonia, nine species in Polynesia, five species in India, and two species in Senegal. These data support a worldwide distribution of Malassezia sp., Trichosporon sp., and Candida sp. in the gut mycobiome. Here, 13 fungal species and two protists, Stentor roeseli and Vorticella campanula, were observed for first time in the human gut. This study revealed a previously unsuspected diversity in the repertoire of human gut microeukaryotes, suggesting spots for further exploring this repertoire.

Growth advantage of Streptococcus thermophilus over Lactobacillus bulgaricus in vitro and in the gastrointestinal tract of gnotobiotic rats

The yoghurt bacteria, Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus, are alleged to have beneficial effects on human health. The objective of this study was to characterise growth, biochemical activity and competitive behaviour of these two bacteria in vitro and in vivo. S. thermophilus LMD-9 and L. bulgaricus ATCC 11842 growth and lactate production were monitored in different media and in the gastrointestinal tract (GIT) of germ-free rats. In vitro, particularly in milk, S. thermophilus had a selective growth advantage over L. bulgaricus. The GIT of germ-free rats not supplemented with lactose was colonised by S. thermophilus but not by L. bulgaricus. Both bacteria were able to colonise the GIT of germ-free rats supplemented with 45 g/l lactose in their drinking water. However, if germ-free rats were inoculated with a mixture of the two bacteria and were supplemented with lactose, S. thermophilus rapidly and extensively colonised the GIT (1010 cfu/g faeces) at the expense of L. bulgaricus, which remained in most cases at levels <102 cfu/g faeces. S. thermophilus specifically produced L-lactate, while L. bulgaricus produced only D-lactate, both in vitro and in vivo. S. thermophilus showed competitive and growth advantage over L. bulgaricus in vitro as well as in vivo in the GIT of germ-free rats and, accordingly, L-lactate was the main lactate isomer produced.

Impact of the metabolic activity of Streptococcus thermophilus on the colon epithelium of gnotobiotic rats

The thermophilic lactic acid bacterium Streptococcus thermophilus is widely and traditionally used in the dairy industry. Despite the vast level of consumption of S. thermophilus through yogurt or probiotic functional food, very few data are available about its physiology in the gastrointestinal tract (GIT). The objective of the present work was to explore both the metabolic activity and host response of S. thermophilus in vivo. Our study profiles the protein expression of S. thermophilus after its adaptation to the GIT of gnotobiotic rats and describes the impact of S. thermophilus colonization on the colonic epithelium. S. thermophilus colonized progressively the GIT of germ-free rats to reach a stable population in 30 days (10(8) cfu/g of feces). This progressive colonization suggested that S. thermophilus undergoes an adaptation process within GIT. Indeed, we showed that the main response of S. thermophilus in the rat's GIT was the massive induction of the glycolysis pathway, leading to formation of lactate in the cecum. At the level of the colonic epithelium, the abundance of monocarboxylic acid transporter mRNAs (SLC16A1 and SLC5A8) and a protein involved in the cell cycle arrest (p27(kip1)) increased in the presence of S. thermophilus compared with germ-free rats. Based on different mono-associated rats harboring two different strains of S. thermophilus (LMD-9 or LMG18311) or weak lactate-producing commensal bacteria (Bacteroides thetaiotaomicron and Ruminococcus gnavus), we propose that lactate could be a signal produced by S. thermophilus and modulating the colon epithelium.

Detection of human intestinal catalase-negative, Gram-positive cocci by rRNA-targeted reverse transcription-PCR

An analytical system based on rRNA-targeted reverse transcription-quantitative PCR (RT-qPCR) for enumeration of catalase-negative, Gram-positive cocci was established. Subgroup- or species-specific primer sets targeting 16S or 23S rRNA from Enterococcus, Streptococcus, and Lactococcus were newly developed. The RT-qPCR method using these primers together with the previously reported primer sets specific for the Enterococcus genus, the Streptococcus genus, and several Streptococcus species was found to be able to quantify the target populations with detection limits of 10(3) to 10(4) cells per gram feces, which was more than 100 times as sensitive as the qPCR method (10(6) to 10(8) cells per gram feces). The RT-qPCR analysis of fecal samples from 24 healthy adult volunteers using the genus-specific primer sets revealed that Enterococcus and Streptococcus were present as intestinal commensals at population levels of log(10) 6.2 +/- 1.4 and 7.5 +/- 0.9 per gram feces (mean +/- standard deviation [SD]), respectively. Detailed investigation using species- or subgroup-specific primer sets revealed that the volunteers harbored unique Enterococcus species, including the E. avium subgroup, the E. faecium subgroup, E. faecalis, the E. casseliflavus subgroup, and E. caccae, while the dominant human intestinal Streptococcus species was found to be S. salivarius. Various Lactococcus species, such as L. lactis subsp. lactis or L. lactis subsp. cremoris, L. garvieae, L. piscium, and L. plantarum, were also detected but at a lower population level (log(10) 4.6 +/- 1.2 per gram feces) and prevalence (33%). These results suggest that the RT-qPCR method enables the accurate and sensitive enumeration of human intestinal subdominant but still important populations, such as Gram-positive cocci.