Bugs as drugs: The role of microbiome in cancer focusing on immunotherapeutics.

The human microbiome comprising microorganisms, their collective genomes and metabolic products has gained tremendous research interest in oncology, as multiple cohorts and case studies have demonstrated discernible interpatient differences in this ecosystem based on clinical variables including disease type, stage, diet, antibiotic usage, cancer treatments, therapeutic responses and toxicities. The modulation of the gut microbiome is the subject of many ongoing preclinical and clinical investigations, through the manipulation of diet, as well as the use of prebiotics, probiotics, specific antibiotics, fecal microbial transplantation, microbial consortia and stool substitutes. Standardization and quality control are needed to maximize the information being generated in this growing field, ranging from technical assays to measure microbiome composition, to methodological aspects in the analysis and reporting of results. Proof-of-mechanism and proof-of-concept clinical trials with appropriate controls are needed to confirm or refute the feasibility, safety and ultimately the clinical utility of human microbiome modulation in cancer patients.

Developments in understanding and applying prebiotics in research and practice-an ISAPP conference paper.

AIMS: The concept of using specific dietary components to selectively modulate the gut microbiota to confer a health benefit, defined as prebiotics, originated in 1995. In 2018, a group of scientists met at the International Scientific Association for Probiotics and Prebiotics annual meeting in Singapore to discuss advances in the prebiotic field, focussing on issues affecting functionality, research methodology and geographical differences. METHODS AND RESULTS: The discussion ranged from examining scientific literature supporting the efficacy of established prebiotics, to the prospects for establishing health benefits associated with novel compounds, isolated from different sources. CONCLUSIONS: While many promising candidate prebiotics from across the globe have been highlighted in preliminary research, there are a limited number with both demonstrated mechanism of action and defined health benefits as required to meet the prebiotic definition. Prebiotics are part of a food industry with increasing market sales, yet there are great disparities in regulations in different countries. Identification and commercialization of new prebiotics with unique health benefits means that regulation must improve and remain up-to-date so as not to risk stifling research with potential health benefits for humans and other animals. SIGNIFICANCE AND IMPACT OF STUDY: This summary of the workshop discussions indicates potential avenues for expanding the range of prebiotic substrates, delivery methods to enhance health benefits for the end consumer and guidance to better elucidate their activities in human studies.

Effects of Probiotics, Prebiotics, and Synbiotics on Calcium Homeostasis and Bone Health With Aging: A Systematic Review.

BACKGROUND: Calcium homeostasis and bone health are an increasing concern for middle-aged and older adults. Many studies have explored the positive effects of probiotics, prebiotics, or synbiotics on serum calcium and bone mineral density (BMD) or other parameters related to bone health. However, the participants, the species, doses and duration of interventions, outcomes, and measurements varied among these studies. AIMS: To systematically evaluate the effect of probiotics, prebiotics, or synbiotics on maintaining calcium homeostasis and improving bone health in middle-aged and older adults. METHODS: We identified studies in Cochrane Library, Embase, PubMed, Web of Science, CINAHL, China National Knowledge Infrastructure, and Wanfang and articles in English and Chinese published from inception up to January 10, 2019. Randomized controlled trials (RCTs) involving probiotics, prebiotics, or synbiotics for middle-aged or older adults were employed for meta-analysis by using RevMan 5.3, and heterogeneity and risk of bias assessment were performed. RESULTS: A total of eight studies, involving 564 participants, were included. Probiotics, prebiotics, or synbiotics supplementation was able to significantly elevate serum calcium levels (0.52 mg/dl, 95% CI [0.38, 0.66]), heterogeneity: p = .13, I2  = 44%), while the results of meta-analysis failed to support the effects of this supplementation on the parameters related to bone health in middle-aged and older adults, including BMD, parathyroid hormone, osteocalcin, and alkaline phosphatase. LINKING EVIDENCE TO ACTION: Probiotics, prebiotics, or synbiotics supplementation exerts a facilitating influence on the level of serum calcium, while the present study has not yet supported the beneficial effects of such interventions on bone health. Therefore, further studies with high-quality RCTs are required to determine the effects of probiotics, prebiotics, or synbiotics supplementation on middle-aged and older adults.

Establishing What Constitutes a Healthy Human Gut Microbiome: State of the Science, Regulatory Considerations, and Future Directions.

On December 17, 2018, the North American branch of the International Life Sciences Institute (ILSI North America) convened a workshop "Can We Begin to Define a Healthy Gut Microbiome Through Quantifiable Characteristics?" with >40 invited academic, government, and industry experts in Washington, DC. The workshop objectives were to 1) develop a collective expert assessment of the state of the evidence on the human gut microbiome and associated human health benefits, 2) see if there was sufficient evidence to establish measurable gut microbiome characteristics that could serve as indicators of "health," 3) identify short- and long-term research needs to fully characterize healthy gut microbiome-host relationships, and 4) publish the findings. Conclusions were as follows: 1) mechanistic links of specific changes in gut microbiome structure with function or markers of human health are not yet established; 2) it is not established if dysbiosis is a cause, consequence, or both of changes in human gut epithelial function and disease; 3) microbiome communities are highly individualized, show a high degree of interindividual variation to perturbation, and tend to be stable over years; 4) the complexity of microbiome-host interactions requires a comprehensive, multidisciplinary research agenda to elucidate relationships between gut microbiome and host health; 5) biomarkers and/or surrogate indicators of host function and pathogenic processes based on the microbiome need to be determined and validated, along with normal ranges, using approaches similar to those used to establish biomarkers and/or surrogate indicators based on host metabolic phenotypes; 6) future studies measuring responses to an exposure or intervention need to combine validated microbiome-related biomarkers and/or surrogate indicators with multiomics characterization of the microbiome; and 7) because static genetic sampling misses important short- and long-term microbiome-related dynamic changes to host health, future studies must be powered to account for inter- and intraindividual variation and should use repeated measures within individuals.

Assessing the effects of different prebiotic dietary oligosaccharides in sheep milk ice cream.

The objective of this study was to assess the effects of different prebiotic dietary oligosaccharides (inulin, fructo-oligosaccharide, galacto-oligossacaride, short-chain fructo-oligosaccharide, resistant starch, corn dietary oligosaccharide and polydextrose) in non-fat sheep milk ice cream processing through physical parameters, water mobility and thermal analysis. Overall, the fat replacement by dietary prebiotic oligosaccharides significantly decreased the melting time, melting temperature and the fraction and relaxation time for fat and bound water (T22) while increased the white intensity and glass transition temperature. The replacement of sheep milk fat by prebiotics in sheep milk ice cream constitutes an interesting option to enhance nutritional aspects and develop a functional food.

In ovo validation model to assess the efficacy of commercial prebiotics on broiler performance and oxidative stability of meat.

The purpose of this study was to examine the effect of in ovo injection of 2 different prebiotics, DiNovo (DN; Laminaria spp., extract containing laminarin and fucoidan) and Bi2tos (BI; non-digestive trans-galactooligosaccharides from milk lactose digested with Bifidobacterium bifidum NCIMB 41171), on growth, slaughter traits, intramuscular fat percentage (IF) and muscle fiber diameter, and lipid oxidation of meat in chickens reared under commercial conditions, following an in ovo trial protocol. On d 12 of embryonic incubation, 350,560 Ross 308 eggs were randomly divided into 3 experimental groups and automatically injected in ovo with: physiological saline (control group), BI at dose of 3.5 mg/embryo and DN at dose of 0.88 mg/embryo. Hatched chicks (males and females) were allocated dependent on treatment group into 3 poultry houses on each farm (3 farms in total) with a stocking density of 21.2 to 21.5 chicks/m2 At 42 d of age, 14 randomly chosen birds (7 males and 7 females), per each treatment from each farm, were individually weighed and slaughtered. The results showed no significant differences of final number of chickens/chicken house, mortality, BW per treatment, stocking density (kg/m2), feed intake, feed conversion rate (FCR), and European Broiler Index among 3 experimental groups. Treatments with BI and DN were associated with slight increases (P > 0.05) in average BW and a minor improvement (P > 0.05) of FCR in BI group. Slaughtered chickens from DN and BI treated groups had significantly increase of BW, carcass weight, carcass yield, and breast muscle weight compared with the control group. IF and muscle fiber diameter were similar among groups. Males had significantly higher slaughter traits compared to females, except for breast muscle yield. The prebiotic treatments led to a higher lipid oxidation in meat, even if the detected TBA reactive substances were below the critical value recognized for meat acceptability. In conclusion, in ovo administration of prebiotics was associated with improvements in a number of parameters of relevance to commercial poultry production.

Effect of feeding Jerusalem artichoke (Helianthus tuberosus) root as prebiotic on nutrient utilization, fecal characteristics and serum metabolite profile of captive Indian leopard (Panthera pardus fusca) fed a meat-on-bone diet.

An experiment was conducted to determine the effect of incorporating Jerusalem artichoke (JA) as a prebiotic in the diet of Indian leopards (n = 11 adults) fed a meat-on-bone diet. The trial consisted of three periods (A1 , B, and A2 ). Each period comprised 17 days of adaptation and four days of collection. During the control periods (A1 and A2 ), the leopards were fed their normal zoo diets of 2.5-3 kg of buffalo meat-on-bone six days a week without any supplement. During trial B, meat-on-bone diets of the leopards were supplemented with JA at 2% of dietary dry matter (DM). Meat consumption was similar among the treatments. Supplementation of JA decreased the digestibility of crude protein (P < 0.01). Digestibilities of organic matter and ether extract were similar among the treatments. Serum concentrations of urea and triglycerides were lower (P < 0.05) when JA was added to the diet. Incorporation of JA to the basal diet increased fecal concentrations of acetate (P < 0.01), butyrate (P < 0.01), lactate (P < 0.01), Lactobacillus spp., and Bifidobacterium spp. (P < 0.01) with a simultaneous decrease in the concentration of ammonia (P < 0.01), Clostridia spp. (P < 0.01), and fecal pH (P < 0.01). Fecal microbial profiles and hind gut fermentation were improved, without any adverse effects on feed consumption, nutrient utilization, and serum metabolite profiles. Results of this experiment showed that feeding JA at 2% DM in the whole diet could be potentially beneficial for captive Indian leopards fed meat-on-bone diets.

Application of evidence on probiotics, prebiotics and synbiotics by food industry: a descriptive study.

BACKGROUND: This study assessed how the food industry applies the knowledge and evidence gained from synbiotics, probiotics or prebiotics research in infants, on the general paediatric population. This study also explored: what happens after the clinical trials using infant formula are completed, data is published or remains unpublished; the effectiveness and type of medium the formula manufacturers use to educate consumers on probiotic, prebiotic or synbiotic infant formula. FINDINGS: This was a descriptive study (a survey) that used a structured questionnaire. All listed companies that manufacture and / or market food products with added probiotics, prebiotics or synbiotics for infants were identified and invited to participate. People responsible for research and development were invited to participate in the survey. A letter of invitation was sent to selected participants and if they expressed willingness to take part in the study, a questionnaire with a written consent form was sent. Descriptive statistics and associations between categorical variables were to be tested using a Chi-square test, a p < 0.05 was statistically significant.A total of 25 major infant formulas, baby food manufacturers were identified, invited to participate in the survey. No company was willing to participate in the survey for different reasons: failure to take any action 5 (20%), decision to participate indefinitely delayed 2 (8%), sensitivity of requested information 3 (12%), company does not conduct clinical trials 1 (4%), company declined without further information 4 (16%), erroneous contact information 6 (24%), refusal by receptionists to forward telephone calls to appropriate staff 3 (12%), language barrier 3 (12%), company no longer agrees to market research 1 (4%). CONCLUSION: Due to a poor response rate in this study, no conclusion could be drawn on how the food industry applies evidence gained through probiotics, prebiotics or synbiotics research on infants for the benefit of the general paediatric population. More information and greater transparency is needed from the infant formula manufacturers on how they apply the evidence gained from the research on probiotics, prebiotics and synbiotics on infants.

Probiotics and prebiotics: prospects for public health and nutritional recommendations.

Probiotics and prebiotics are useful interventions for improving human health through direct or indirect effects on the colonizing microbiota. However, translation of these research findings into nutritional recommendations and public health policy endorsements has not been achieved in a manner consistent with the strength of the evidence. More progress has been made with clinical recommendations. Conclusions include that beneficial cultures, including probiotics and live cultures in fermented foods, can contribute towards the health of the general population; prebiotics, in part due to their function as a special type of soluble fiber, can contribute to the health of the general population; and a number of challenges must be addressed in order to fully realize probiotic and prebiotic benefits, including the need for greater awareness of the accumulated evidence on probiotics and prebiotics among policy makers, strategies to cope with regulatory roadblocks to research, and high-quality human trials that address outstanding research questions in the field.

Health claims substantiation for probiotic and prebiotic products.

The topic of "Health Claims Substantiation for Probiotic and Prebiotic Products" was discussed at the 8 (th) annual International Scientific Association for Probiotics and Prebiotics (ISAPP) meeting. The topic is especially timely considering that the regulatory review process for health benefit claims on probiotic and prebiotic products in Europe has not resulted in a single claim being approved (120 negative opinions on probiotic claims and 19 negative opinions on prebiotic claims through February 2011). This situation in Europe and elsewhere has driven companies to seek clarity on a research path that would stand up to scientific scrutiny as well as satisfy regulatory demands for health claim substantiation. It can be challenging to negotiate rigid regulatory distinctions, such as between health and disease, when these states are more realistically represented by continua. One research approach focused on improved homeostasis is explored as a statistically robust approach to measuring physiological parameters in healthy populations, which are the required target for food and supplement claims. Diverse global regulatory frameworks complicate this issue, and harmonization of different approaches globally would simplify requirements for industry, decrease consumer confusion and improve the scientific framework for the research community to set up appropriate research pathways. This report highlights key points from this discussion. 

Oligosaccharide-induced whey-specific CD25(+) regulatory T-cells are involved in the suppression of cow milk allergy in mice.

Dietary intervention with a unique prebiotic nondigestible carbohydrate mixture has been shown to reduce the development of allergic disease in infants at risk. In this study, the involvement of CD25(+) regulatory T-cells (Treg) in the carbohydrate-induced effects was investigated in mice orally sensitized with whey using adoptive transfer experiments. Donor mice were sensitized with whey and fed a diet containing short-chain galacto-, long-chain fructo- and acidic-oligosaccharides, or a control diet starting 2 wk before sensitization. The acute allergic skin reaction upon intradermal whey challenge was determined and whey-specific Ig were measured. Splenocytes of the donor mice were transferred to naïve recipient mice after partial ex vivo depletion of CD25(+) Treg. The prebiotic diet clearly diminished the acute allergic skin reaction (P < 0.001). Whey-sensitized recipient mice transferred with splenocytes from whey-sensitized, prebiotic-fed donor mice displayed almost complete prevention of the acute allergic skin reaction compared with mice receiving cells from sham-sensitized, prebiotic-fed donor mice (P < 0.001). Partial depletion of CD25(+) T-cells inhibited these effects (P < 0.001), although IgE sensitization was not prevented. This study indicates the involvement of whey-specific CD25(+) Treg in the suppression of the allergic effector response induced by dietary intervention with prebiotics.