Functional cultures and health benefits

Bacteriocin production: a relatively unharnessed probiotic trait?

Probiotics are “live microorganisms which, when consumed in adequate amounts, confer a health benefit to the host”. A number of attributes are highly sought after among these microorganisms, including immunomodulation, epithelial barrier maintenance, competitive exclusion, production of short-chain fatty acids, and bile salt metabolism. Bacteriocin production is also generally regarded as a probiotic trait, but it can be argued that, in contrast to other traits, it is often considered a feature that is desirable, rather than a key probiotic trait. As such, the true potential of these antimicrobials has yet to be realised.

Exploring the relationship between exposure to technological and gastrointestinal stress and probiotic functional properties of lactobacilli and bifidobacteria

Strains of Lactobacillus and Bifidobacterium are considered probiotic because of their associated potential health benefits. Probiotics are commonly administered orally via incorporation into food products. Microorganisms for use as probiotics encounter stress conditions, which include acid, bile, osmotic, oxidative, heat and cold stresses. These can occur during processing and storage and during passage through the gastrointestinal tract, and can affect viability. Probiotic bacteria have to remain viable to confer any health benefits. Therefore, the ability to withstand technological and gastrointestinal stresses is crucial probiotic selection criteria. While the stress tolerance mechanisms of lactobacilli and bifidobacteria are largely understood, the impact of exposure to stressful conditions on the functional properties of surviving probiotic microorganisms is not clear. This review explores the potentially positive and negative relationships between exposure to stress conditions and probiotic functional properties, such as resistance to gastric acid and bile, adhesion and colonization potential, and tolerance to antibiotics. Protective strategies can be employed to combat negative effects of stress on functional properties. However, further research is needed to ascertain synergistic relationships between exposure to stress and probiotic properties.

Probiotics production and alternative encapsulation methodologies to improve their viabilities under adverse environmental conditions

Probiotic products are dietary supplements containing live microorganisms producing beneficial health effects on the host by improving intestinal balance and nutrient absorption. Among probiotic microorganisms, those classified as lactic acid bacteria are of major importance to the food and feed industries. Probiotic cells can be produced using alternative carbon and nitrogen sources, such as agroindustrial residues, at the same time contributing to reduce process costs. On the other hand, the survival of probiotic cells in formulated food products, as well as in the host gut, is an essential nutritional aspect concerning health benefits. Therefore, several cell microencapsulation techniques have been investigated as a way to improve cell viability and survival under adverse environmental conditions, such as the gastrointestinal milieu of hosts. In this review, different aspects of probiotic cells and technologies of their related products are discussed, including formulation of culture media, and aspects of cell microencapsulation techniques required to improve their survival in the host.

Whole-cell detection of live lactobacillus acidophilus on aptamer-decorated porous silicon biosensors

This work describes the design of optical aptamer-based porous silicon (PSi) biosensors for the direct capture of Lactobacillus acidophilus. Aptamers are oligonucleotides (single-stranded DNA or RNA) that can bind their targets with high affinity and specificity, making them excellent recognition elements for biosensing applications. Herein, aptamer Hemag1P, which specifically targets the important probiotic L. acidophilus, was utilized for direct bacteria capture onto oxidized PSi Fabry-Pérot thin films. Monitoring changes in the reflectivity spectrum (using reflective interferometric Fourier transform spectroscopy) allows for bacteria detection in a label-free, simple and rapid manner. The performance of the biosensor was optimized by tuning the PSi nanostructure, its optical properties, as well as the immobilization density of the aptamer. We demonstrate the high selectivity and specificity of this simple "direct-capture" biosensing scheme and show its ability to distinguish between live and dead bacteria. The resulting biosensor presents a robust and rapid method for the specific detection of live L. acidophilus at concentrations relevant for probiotic products and as low as 10(6) cells per mL. Rapid monitoring of probiotic bacteria is crucial for quality, purity and safety control as the use of probiotics in functional foods and pharmaceuticals is becoming increasingly popular.

Effect of Wheat Dietary Fiber Particle Size during Digestion In Vitro on Bile Acid, Faecal Bacteria and Short-Chain Fatty Acid Content

The influence of bile acid concentration on the growth of Bifidobacterium spp. and Lactobacillus spp. bacteria was demonstrated. Exposing these bacteria to the environment containing bile acid salts, and very poor in nutrients, leads to the disappearance of these microorganisms due to the toxic effect of bile acids. A multidimensional analysis of data in the form of principal component analysis indicated that lactic acid bacteria bind bile acids and show antagonistic effect on E. coli spp. bacteria. The growth in E. coli spp. population was accompanied by a decline in the population of Bifidobacterium spp. and Lactobacillus spp. with a simultaneous reduction in the concentration of bile acids. This is direct proof of acid binding ability of the tested lactic acid bacteria with respect to cholic acid, lithocholic acid and deoxycholic acid. This research demonstrated that the degree of fineness of wheat dietary fibre does not affect the sorption of bile acids and growth of some bacteria species; however, it has an impact on the profile of synthesized short-chained fatty acids. During the digestion of a very fine wheat fibre fraction (WF 90), an increase in the concentration of propionic and butyric acids, as compared with the wheat fiber fraction of larger particles - WF 500, was observed. Our study suggested that wheat fibre did not affect faecal bacteria growth, however, we observed binding of bile acids by Bifidobacterium spp. and Lactobacillus spp.

Effect of immobilisation materials on viability and fermentation activity of dairy starter culture in whey-based substrate

BACKGROUND

The main objectives of the paper were to study influence of immobilisation of dairy starter culture 'Lactoferm ABY 6' on fermentation and probiotic potential of fermented whey-based substrate.

RESULTS

Fermentation with free cells takes 1.5 h less than fermentation with encapsulated cells, but samples with encapsulated cells have better characteristics after 28 days of storage. Chitosan coating provides additional protection of cells in bile salt solution (95.86% of viable cells compared to the initial number) and simulated gastric juice (37.8% for pH 2.5) compared to the alginate beads (94.54% in bile salt solution and 36.18% in simulated gastric juice for pH 2.5). Free cells had a drastic reduction in the number of viable cells (83.0% in bile salt solution and no viable cells in simulated gastric juice for pH 2.5).

CONCLUSION

Samples with alginate beads and chitosan-coated alginate beads have significantly (P < 0.05) higher viable cell count than samples with free cells, during 4 h monitoring survival at pH 2.5, pH 3.0 and 0.3% bovine bile solution. These beads can be used to improve survival of probiotic cells in fermented whey-based beverage during storage and consummation, which improves the quality of the product.

Influence of probiotics, included in peanut butter, on the fate of selected Salmonella and Listeria strains under simulated gastrointestinal conditions

AIMS

This study observed the behaviour of probiotics and selected bacterial pathogens co-inoculated into peanut butter during gastrointestinal simulation.

METHODS AND RESULTS

Peanut butter homogenates co-inoculated with Salmonella/Listeria strains (5 log CFU ml(-1) ) and lyophilized or cultured probiotics (9 log CFU ml(-1) ) were exposed to simulated gastrointestinal conditions for 24 h at 37°C. Sample pH, titratable acidity and pathogen populations were determined. Agar diffusion assay was performed to assess the inhibitory effect of probiotic culture supernatants with either natural (3·80 (Lactobacillus), 3·78 (Bifidobacteirum) and 5·17 (Streptococcus/Lactococcus)) or neutralized (6·0) pH. Antibacterial effect of crude bacteriocin extracts were also evaluated against the pathogens. After 24 h, samples with probiotics had lower pH and higher titratable acidity than those without probiotics. The presence of probiotics caused a significant reduction (P < 0·05) in pathogen populations. Supernatants of Bifidobacterium and Lactobacillus cultures inhibited pathogen growth; however, the elevation of pH diminished their antibacterial activities. Crude bacteriocin extracts had a strain-specific inhibitory effect only towards Listeria monocytogenes.

CONCLUSION

Probiotics in 'peanut butter' survived simulated gastrointestinal conditions and inhibited the growth of Salmonella/Listeria.

SIGNIFICANCE AND IMPACT OF THE STUDY

Peanut butter is a plausible carrier to deliver probiotics to improve the gastrointestinal health of children in developing countries.

Effects of Prebiotic and Synbiotic Supplementation on Inflammatory Markers and Anthropometric Indices After Roux-en-Y Gastric Bypass: A Randomized, Triple-blind, Placebo-controlled Pilot Study

BACKGROUND

Studies have shown that prebiotics and synbiotics modulate the intestinal microbiota and may have beneficial effects on the immune response and anthropometric indices; however, the impact of the use of these supplements after bariatric surgery is not yet known.

GOALS

This study investigated the effects of prebiotic and synbiotic supplementation on inflammatory markers and anthropometric indices in individuals undergoing open Roux-en-Y gastric bypass (RYGB).

STUDY

In this randomized, controlled, and triple-blind trial conducted as a pilot study, individuals undergoing RYGB (n=9) and healthy individuals (n=9) were supplemented with 6 g/d of placebo (maltodextrin), prebiotic (fructo-oligosaccharide, FOS), or synbiotic (FOS+Lactobacillus and Bifidobacteria strains) for 15 days.

RESULTS

Interleukin-1β, interleukin-6, tumor necrosis factor-α, C-reactive protein, albumin, and the C-reactive protein/albumin ratio showed no significant changes on comparison between groups after supplementation. The reduction in the body weight of patients undergoing RYGB was 53.8% higher in the prebiotic group compared with the placebo group (-0.7 kg, P=0.001), whereas the reduction in the BMI and the increase in the percentage of excess weight loss were higher in the placebo and the prebiotic groups compared with the synbiotic group (P<0.05).

CONCLUSIONS

Supplementation of FOS increased weight loss, whereas both prebiotics and synbiotics were not able to promote significant changes in inflammatory markers, although in most analyses, there was a reduction in their absolute values. The use of FOS may represent a potential adjunct in the treatment of obesity.

Physicochemical, microbiological and spoilage analysis of probiotic processed cheese analogues with reduced emulsifying salts during refrigerated storage

Microbial quality of low-salt processed cheeses supplemented with Bacillus coagulans spores (10(7)-10(8) CFU/g) relying on their physicochemical characteristics during 60 day-cold storage was evaluated. A reduction in moisture content, water activity and pH value and a significant enhancement in proteolytic index of control and probiotic samples were obtained by prolonging storage time. Survival rate of the probiotic cells significantly decreased up to day 30, while total count of the viable cells increased by increasing storage time. A 20 and 67 % increase in total counts of coliforms and mold-yeast of the control sample were respectively observed after 60 days of cold storage. A considerable decrease in the total counts of coliforms and mold-yeast was also found in the processed cheeses containing probiotic supplement. According to the macroscopic and sensory assessment, off-odors and off-flavors in the control sample were diagnosed after day 1 of cold-storage. Noticeably, the resistance to spoilage was more prominent in samples containing the probiotic cells.

Non-Conventional Tools to Preserve and Prolong the Quality of Minimally-Processed Fruits and Vegetables

The main topic of this paper is a focus on some non-conventional tools to preserve the microbiological and physico-chemical quality of fresh-cut fruits and vegetables. The quality of fresh-cut foods is the result of a complex equilibrium involving surface microbiota, storage temperature, gas in the headspace and the use of antimicrobials. This paper proposes a short overview of some non-conventional approaches able to preserve the quality of this kind of product, with a special focus on some new ways, as follows: (1) use of edible or antimicrobial-containing coatings (e.g., chitosan-based coatings) on fruits or vegetables; (2) alternative modified atmospheres (e.g., high O2-modified atmosphere packaging (MAP)) or the use of essential oils in the headspace; (3) conditioning solutions with antimicrobials or natural compounds for fruit salad; and (4) biopreservation and use of a probiotic coating.

Probiotic Characteristics of Lactobacillus plantarum FH185 Isolated from Human Feces

Lactobacillus plantarum FH185 was isolated from the feces of healthy adults. In our previous study, L. plantarum FH185 was demonstrated that it has anti-obesity effect in the in vitro and in vivo test. In order to determine its potential for use as a probiotic, we investigated the physiological characteristics of L. plantarum FH185. The optimum growth temperature of L. plantarum FH185 was 40℃. L. plantarum FH185 showed higher sensitivity to novobiocin in a comparison of fifteen different antibiotics and showed higher resistance to polymyxin B and vancomycin. It also showed higher β-galactosidase and N-acetyl-β-glucosaminidase activities. Moreover, it was comparatively tolerant to bile juice and acid, and inhibited the growths of Salmonella Typhimurium and Staphylococcus aureus with rates of 44.76% and 53.88%, respectively. It also showed high adhesion activity to HT-29 cells compared to L. rhamnosus GG.

Trends in dairy and non-dairy probiotic products - a review

Health awareness has grown to a greater extent among consumers and they are looking for healthy probiotic counterparts. Keeping in this view, the present review focuses recent developments in dairy and non-dairy probiotic products. All over the world, dairy probiotics are being commercialized in many different forms. However, the allergy and lactose intolerance are the major set-backs to dairy probiotics. Whereas, flavor and refreshing nature are the major advantages of non-dairy drinks, especially fruit juices. Phenotypic and genotypic similarities between dairy and non-dairy probiotics along with the matrix dependency of cell viability and cell functionality are reviewed. The heterogeneous food matrices of non-dairy food carriers are the major constraints for the survival of the probiotics, while the probiotic strains from non-dairy sources are satisfactory. Technological and functional properties, besides the viability of the probiotics used in fermented products of non-dairy origin are extremely important to get a competitive advantage in the world market. The functional attributes of dairy and non-dairy probiotic products are further enhanced by adding prebiotics such as galacto-oligosaccharide, fructo-oligosaccharide and inulin.

Microencapsulation of Lactobacillus plantarum MTCC 5422 in fructooligosaccharide and whey protein wall systems and its impact on noodle quality

Noodles are staple cereal food in many countries; however addition of encapsulated probiotics into noodle formulation, its effect on noodle quality and cell viability has not yet been reported. The aim of this study was to prepare microencapsulated Lactobacillus plantarum (MTCC 5422) by freeze drying with wall material combinations such as fructooligosaccharide (FOS), FOS + whey protein isolate (WPI), and FOS + denatured whey protein isolate (DWPI) to evaluate best wall system. Results showed that FOS + DWPI wall system provided better protection to cells after drying, during storage (60 days, 4 °C) and in simulated acidic and bile conditions. Further, FOS + DWPI encapsulates were incorporated into noodle formulation and evaluated the noodle quality and probiotic cell viability of cooked noodle obtained from two different production methods: (i) fresh and (ii) dried (room temperature dried - RTD, 28 °C and high temperature dried - HTD, 55 °C). The quality characteristics (cooking time, solid loss, texture, colour and sensory profiles) of FOS + DWPI encapsulates incorporated cooked noodles (both fresh and dried) were found to be acceptable. On evaluation of encapsulated probiotic bacteriaL. plantarum cell viability, 93.63 % and 62.42 % cell survival was obtained in fresh noodles before and after cooking respectively. However, 80.29 % (RTD) and 64.74 % (HTD) of encapsulated cells were viable in dried noodles, after cooking there was complete survival loss. This study suggested that fresh noodle was found to be a suitable carrier system to deliver viable cells. This is first report on influence of probiotic microcapsules in noodle processing.

Enhancement of bile resistance in Lactobacillus plantarum strains by soy lecithin

This study evaluated the effect of soy lecithin on the bile resistance of Lactobacillus plantarum. Six strains were cultured in MRS broth supplemented with soy lecithin at different concentrations. The strains incubated in MRS broth with 1·0% soy lecithin showed no inhibitory effect on cell growth. After culturing in MRS broth with 0·2-1·0% soy lecithin, the survival rate of harvested cells increased significantly (P < 0·05) in the 0·3% bile challenge compared with the no added soy lecithin group. The cells incubated with 0·6% soy lecithin were able to grow in an MRS broth with a higher bile salt content. The surface hydrophobicity and cell leakage in the bile challenge were assessed to reveal the physical changes caused by the addition of soy lecithin. The cell surface hydrophobicity was enhanced and the membrane integrity in the bile challenge increased after culturing with soy lecithin. A shift in the fatty acid composition was also observed, illustrating the cell membrane change in the soy lecithin culture.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, we report for the first time the beneficial effect of adding soy lecithin to an MRS broth on subsequent bile tolerance of Lactobacillus plantarum. Soy lecithin had no inhibitory effect on strain viability but significantly enhanced bile resistance. Surface hydrophobicity and cell integrity increased in strains cultured with soy lecithin. The observed shift in the cell fatty acid composition indicated changes to the cell membrane. As soy lecithin is safe for use in the food industry, its protective effects can be harnessed for the development of bile-sensitive strains with health-benefit functions for use in probiotic products.

In vitro study of beneficial properties and safety of lactic acid bacteria isolated from Portuguese fermented meat products

Many lactic acid bacteria produce bacteriocins with a rather broad spectrum of inhibition, which could offer potential applications in food preservation. Bacteriocin production by starter cultures may bring advantage to these strains in competitive interactions with pathogenic bacteria from the food matrix. The objective of this study was to determine the safety of beneficial strains (Lactobacillus plantarum ST202Ch and ST216Ch, Enterococcus faecium ST211Ch, and Lactobacillus sakei ST22Ch, ST153Ch and ST154Ch) previously isolated from fermented meat products and characterised as bacteriocin producers. Auto-aggregation was strain-specific, and values of 28.97, 27.86 and 28.56% were recorded for L. sakei ST22Ch, ST153Ch and ST154Ch, respectively, 16.95 and 14.58% for L. plantarum ST202Ch and ST216Ch, respectively, and 12.77% for E. faecium ST211Ch. Various degrees of co-aggregation between 28.85 and 44.76% for Listeria monocytogenes 211 and 409, and between 23.60 to 34.96% for E. faecium ATCC 19443 were observed. According to the results of the diffusion method, the studied strains demonstrated susceptibility to penicillin G, ampicillin, amoxicillin, amoxicillin/clavulonic acid, imipenem, linezolid, and tetracycline. In addition, the susceptibility of the six strains to various non-antibiotic commercial drugs was examined. Production of β-galactosidase by L. sakei ST22Ch, ST153Ch and ST154Ch, L. plantarum ST202Ch and ST216Ch, and E. faecium ST211Ch was confirmed by employing sterile filter paper discs impregnated with o-nitrophenyl-β-D-galactopyranose. A statistically significant (P<0.001) inhibition of Mycobacterium tuberculosis growth by bacteriocins produced by L. plantarum ST202Ch (38.3%) and ST216Ch (48.6%), L. sakei ST153Ch (16.2%) and ST154Ch (16.1%), and E. faecium ST211Ch (21.7%) was observed. As determined by the polymerase chain reaction, the tested strains showed a low virulence gene profile.

Applications of microencapsulated Bifidobacterium longum with Eleutherine americana in fresh milk tofu and pineapple juice

Bifidobacterium longum was microencapsulated by extrusion technique and added in fresh milk tofu and pineapple juice. Microencapsulation of B. longum with Eleutherine americana extract, oligosaccharides extract, and commercial fructo-oligosaccharides was assessed for the bacterial survival after sequential exposure to simulated gastric and intestinal juices, and refrigeration storage. Microencapsulated B. longum with the extract and oligosaccharides extract in the food products showed better survival than free cells under adverse conditions. Sensory analysis demonstrated that the products containing co-encapsulated bacterial cells were more acceptable by consumers than free cells. Pineapple juice prepared with co-encapsulated cells had lower values for over acidification, compared with the juice with free cells added. This work suggested that microencapsulated B. longum with E. americana could enhance functional properties of fresh milk tofu and pineapple juice.

Selenite-stress selected mutant strains of probiotic bacteria for Se source production

Selenium deficiency is a major health problem worldwide for about 1 billion people. Bacterial cells usually possess low tolerance to selenite stress and also low ability to reduce high concentrations of toxic selenite. Here, high tolerance to selenite and selenium bioaccumulation capability were developed in mutated clones of probiotic and starter bacteria including Enterococcus faecium, Bifidobacterium animalis ssp. lactis, Lactobacillus casei and Lactococcus lactis ssp. lactis by food-level strain development process and clone selection. All mutant clones possessed increased glutathione concentration and glutathione reductase activity. The selenite treatment increased further these values in L. casei mutant strain pointing at a different selenite reduction pathway and/or stress response in this organism. Considerable conversion of selenite to cell bound selenium forms with a concomitant high biomass production was detected in E. faecium and B. animalis ssp. lactis cultures. Possible application of these strains as food and feed supplements is under investigation.

Biocheese: a food probiotic carrier

This review describes some aspects related to the technological barriers encountered in the development and stability of probiotic cheeses. Aspects concerning the viability of probiotic cultures in this matrix are discussed and the potential of cheese as a biofunctional food carrier is analyzed, outlying some points related to health and safety. In general, the manufacture of probiotic cheese should have little change when compared with the elaboration of cheese in the traditional way. The physicochemical and technological parameters influencing the quality of these products have also to be measured so as to obtain a process optimization.

Lactobacillus reuteri I5007 modulates tight junction protein expression in IPEC-J2 cells with LPS stimulation and in newborn piglets under normal conditions

Background

Tight junctions (TJs) maintain the intestinal mucosal barrier, dysfunction of which plays a vital role in the pathophysiology of a variety of gastrointestinal disorders. Previously, we have shown that L. reuteri I5007 maintained the gut epithelial barrier in newborn piglets. Here we aimed to decipher the influence of L. reuteri I5007 on tight junction (TJ) protein expression both in vivo and in vitro.

Results

We found that L. reuteri I5007 significantly increased the protein abundance of intestinal epithelial claudin-1, occludin and zonula occluden-1 (ZO-1) in newborn piglets (orally administrated with 6 × 10⁹ CFU of L. reuteri I5007 daily for 14 days). In vitro, treatment with L. reuteri I5007 alone maintained the transepithelial electrical resistance (TEER) of IPEC-J2 cells with time. In addition, IPEC-J2 cells were stimulated with 1 μg/mL lipopolysaccharide (LPS) for 1, 4, 8, 12 or 24 h, following pre-treatment with L. reuteri I5007 or its culture supernatant for 2 h. The results showed that LPS time-dependently induced (significantly after 4 or 8 h) the expression of TNF-α and IL-6, and decreased TJ proteins, which was reversed by pre-treatment of L. reuteri I5007 or its culture supernatant.

Conclusions

L. reuteri I5007 had beneficial effects on the expression of TJ proteins in newborn piglets and the in-vitro results showed this strain had a positive effect on TEER of cells and inhibited the reduction of TJ proteins expression induced by LPS. These findings indicated L. reuteri I5007 may have potential roles in protection TJ proteins in TJ-deficient conditions.

Novel approaches to improve the intrinsic microbiological safety of powdered infant milk formula

Human milk is recognised as the best form of nutrition for infants. However; in instances where breast-feeding is not possible, unsuitable or inadequate, infant milk formulae are used as breast milk substitutes. These formulae are designed to provide infants with optimum nutrition for normal growth and development and are available in either powdered or liquid forms. Powdered infant formula is widely used for convenience and economic reasons. However; current manufacturing processes are not capable of producing a sterile powdered infant formula. Due to their immature immune systems and permeable gastro-intestinal tracts, infants can be more susceptible to infection via foodborne pathogenic bacteria than other age-groups. Consumption of powdered infant formula contaminated by pathogenic microbes can be a cause of serious illness. In this review paper, we discuss the current manufacturing practices present in the infant formula industry, the pathogens of greatest concern, Cronobacter and Salmonella and methods of improving the intrinsic safety of powdered infant formula via the addition of antimicrobials such as: bioactive peptides; organic acids; probiotics and prebiotics.

Preparation of Eleutherine americana-alginate complex microcapsules and application in Bifidobacterium longum

Microencapsulation using extrusion and emulsion techniques was prepared for Bifidobacterium longum protection against sequential exposure to simulated gastric and intestinal juices, refrigeration storage and heat treatment. Eleutherine americana was used as the co-encapsulating agent. Hydrolysis of E. americana by gastric and intestinal juices was also determined. E. americana and its oligosaccharide extract demonstrated their resistance to low pH and partial tolerance to human α-amylase. Microencapsulated B. longum with E. americana and oligosaccharide extract prepared by the extrusion technique survived better than that by the emulsion technique under adverse conditions. Survival of microencapsulated cells after exposure to the juices and refrigeration storage was higher than free cells at Weeks 2 and 4. In addition, the viability of microencapsulated cells was better than free cells at 65 °C for 15 min. This work suggested that microencapsulated B. longum with E. americana offers the effective delivery of probiotics to colon and maintains their survival in food products.

The infant microbiome development: mom matters

The infant microbiome plays an essential role in human health and its assembly is determined by maternal-offspring exchanges of microbiota. This process is affected by several practices, including Cesarean section (C-section), perinatal antibiotics, and formula feeding, that have been linked to increased risks of metabolic and immune diseases. Here we review recent knowledge about the impacts on infant microbiome assembly, discuss preventive and restorative strategies to ameliorate the effects of these impacts, and highlight where research is needed to advance this field and improve the health of future generations.