Development of probiotic products for nutritional requirements of specific human populations

The Therapeutic Role of Exercise and Probiotics in Stressful Brain Conditions

Oxidative stress has been recognized as a contributing factor in aging and in the progression of multiple neurological disorders such as Parkinson’s disease, Alzheimer’s dementia, ischemic stroke, and head and spinal cord injury. The increased production of reactive oxygen species (ROS) has been associated with mitochondrial dysfunction, altered metal homeostasis, and compromised brain antioxidant defence. All these changes have been reported to directly affect synaptic activity and neurotransmission in neurons, leading to cognitive dysfunction. In this context two non-invasive strategies could be employed in an attempt to improve the aforementioned stressful brain status. In this regard, it has been shown that exercise could increase the resistance against oxidative stress, thus providing enhanced neuroprotection. Indeed, there is evidence suggesting that regular physical exercise diminishes BBB permeability as it reinforces antioxidative capacity, reduces oxidative stress, and has anti-inflammatory effects. However, the differential effects of different types of exercise (aerobic exhausted exercise, anaerobic exercise, or the combination of both types) and the duration of physical activity will be also addressed in this review as likely determinants of therapeutic efficacy. The second proposed strategy is related to the use of probiotics, which can also reduce some biomarkers of oxidative stress and inflammatory cytokines, although their underlying mechanisms of action remain unclear. Moreover, various probiotics produce neuroactive molecules that directly or indirectly impact signalling in the brain. In this review, we will discuss how physical activity can be incorporated as a component of therapeutic strategies in oxidative stress-based neurological disorders along with the augmentation of probiotics intake.

Increased incidence of necrotizing enterocolitis associated with routine administration of Infloran™ in extremely preterm infants

We aimed to evaluate the isolation of strains contained in the Infloran™ probiotic preparation in blood cultures and its efficacy in reducing necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) in extremely preterm infants. Routine use of probiotics was implemented in 2008. Infants born at <28 weeks gestational age were prospectively followed and compared with historical controls (HC) born between 2005 and 2008. Data on sepsis due to any of the two probiotic strains contained in Infloran and rates of LOS and NEC were analysed. A total of 516 infants were included. During the probiotic period (PC), none of the strains included in the administered probiotic product were isolated from blood cultures. Probiotic administration was associated with an increase in NEC stage II or higher (HC 10/170 [5.9%]; PC 46/346 [13.3%]; P=0.010). Surgical NEC was 12.1% in PC (42/346) versus 5.9% (10/170) in HC (P=0.029). Adjusting for confounders (sex, gestational age, antenatal steroids and human milk) did not change those trends (P=0.019). Overall, clinical LOS and the incidence of staphylococcal sepsis were lower in PC (172/342, 50.3, and 37%, respectively) compared with HC (102/169, 60.3 and 50.9%, respectively) (P=0.038 and P=0.003, respectively). No episodes of sepsis attributable to the probiotic product were recorded. The period of probiotic administration was associated with an increased incidence of NEC after adjusting for neonatal factors, but also with a reduction in the LOS rate.

Exopolysaccharides Produced by Lactic Acid Bacteria and Bifidobacteria as Fermentable Substrates by the Intestinal Microbiota

The functional food market, including products formulated to maintain a "healthy" gut microbiota, i.e. probiotics and prebiotics, has increased enormously since the end of the last century. In order to favor the competitiveness of this sector, as well as to increase our knowledge of the mechanisms of action upon human health, new probiotic strains and prebiotic substrates are being studied. This review discusses the use of exopolysaccharides (EPS), both homopolysaccharides (HoPS) and heteropolysaccharides (HePS), synthesized by lactic acid bacteria and bifidobacteria as potential prebiotics. These extracellular carbohydrate polymers synthesized by some gut inhabitants seem to be resistant to gastrointestinal digestion; these are susceptible as well to biodegradability by the intestinal microbiota depending on both the physicochemical characteristics of EPS and the pool of glycolytic enzymes harbored by microbiota. Therefore, although the chemical composition of these HoPS and HePS is different, both can be fermentable substrates by intestinal inhabitants and good candidates as prebiotic substrates. However, there are limitations for their use as additives in the food industry due to, on the one hand, their low production yield and, on the other hand, a lack of clinical studies demonstrating the functionality of these biopolymers.

Perinatal Microbiomes' Influence on Preterm Birth and Preterms' Health: Influencing Factors and Modulation Strategies

Microbial communities inhabiting the human host play important roles in maintaining health status, including reproduction and early life programming, which is particularly important in the context of preterm neonates' health. Preterm birth (PTB) is often the result of a microbial dysbiosis or infection. In addition, preterm neonates experience different levels of organ immaturity and an abnormal gut microbiota establishment, as compared to full-term neonates. This exacerbates their developmental problems and can have negative consequences at systemic level. In addition, preterm babies are commonly exposed to delayed enteral feeding and hospital environments, which increases the risk of short- and long-term health problems. Some of these clinical conditions, such as necrotizing enterocolitis or sepsis, may be life threatening, whereas others may translate into life-long conditions, including cognitive problems. Increasing scientific interest has focused on understanding developmental problems in preterm neonates related to abnormalities in the settlement of their microbial communities, with the final goal of selecting appropriate microbiome-targeted strategies (eg, probiotics), to reduce preterm health risks and improve overall quality of life.This review aims to summarize current knowledge on microbiological factors influencing PTB initiation and gastrointestinal development, and on the health consequences to the preterm neonate. Scientific evidences on dietary strategies reducing PTB incidence and minimizing sequelae in this particularly sensitive human group subpopulation are also discussed.

Immune Modulation Capability of Exopolysaccharides Synthesised by Lactic Acid Bacteria and Bifidobacteria

During recent years, the exopolysaccharides (EPS) produced by some strains of lactic acid bacteria and bifidobacteria have attracted the attention of researchers, mainly due to their potential technological applications. However, more recently, it has been observed that some of these EPS present immunomodulatory properties, which suggest a potential effect on human health. Whereas EPS from lactic acid bacteria have been studied in some detail, those of bifidobacteria largely remain uncharacterized in spite of the ubiquity of EPS genes in Bifidobacterium genomes. In this review, we have analysed the data collected in the literature about the potential immune-modulating capability of EPS produced by lactic acid bacteria and bifidobacteria. From this data analysis, as well as from results obtained in our group, a hypothesis relating the physicochemical characteristics of EPS with their immune modulation capability was highlighted. We propose that EPS having negative charge and/or small size (molecular weight) are able to act as mild stimulators of immune cells, whereas those polymers non-charged and with a large size present a suppressive profile.

Capability of exopolysaccharide-producing Lactobacillus paraplantarum BGCG11 and its non-producing isogenic strain NB1, to counteract the effect of enteropathogens upon the epithelial cell line HT29-MTX

The putative protective role of the exopolysaccharide (EPS)-producing Lactobacillus paraplantarum BGCG11, and its non-EPS-producing isogenic strain NB1, was tested upon HT29-MTX monolayers challenged with seven opportunistic pathogens. The probiotic strain Lactobacillus rhamnosus LMG18243 (GG) was used as a reference bacterium. Tested lactobacilli were able to efficiently reduce the attachment to HT29-MTX of most pathogens. Lb. paraplantarum NB1 and Lb. rhamnosus GG were more efficient reducing the adhesion of Clostridium difficile or Yersinia enterocolitica than Lb. paraplantarum BGCG11, while strain BGCG11 reduced, to a greater extent, the adhesion of Escherichia coli and Listeria monocytogenes. The detachment and cell lysis of HT29-MTX monolayers in the presence of pathogens alone and co-incubated with lactobacilli or purified EPS was followed. L. monocytogenes induced the strongest cell detachment among the seven tested pathogens and this effect was prevented by addition of purified EPS-CG11. The results suggest that this EPS could be an effective macromolecule in protection of HT29-MTX cells from the pathogen-induced lysis. Regarding innate intestinal barrier, the presence of C. difficile induced the highest IL-8 production in HT29-MTX cells and this capability was reinforced by the co-incubation with Lb. paraplantarum NB1 and Lb. rhamnosus GG. However, the increase in IL-8 production was not noticed when C. difficile was co-incubated with EPS-producing Lb. paraplantarum BGCG11 strain or its purified EPS-CG11 polymer, thus indicating that the polymer could hinder the contact of bacteria with the intestinal epithelium. The measurement of mucus secreted by HT29-MTX and the expression of muc1, muc2, muc3B and muc5AC genes in the presence of pathogens and lactobacilli suggested that all lactobacilli strains are weak "co-adjuvants" helping some pathogens to slightly increase the secretion of mucus by HT29-MTX, while purified EPS-CG11 did not induce mucus secretion. Taking altogether, Lb. paraplantarum BGCG11 could act towards the reinforcement of the innate mucosal barrier through the synthesis of a physical-protective EPS layer which could make difficult the contact of the pathogens with the epithelial cells.

The neonatal bowel microbiome in health and infection

PURPOSE OF REVIEW

In newborns, interactions between the host and the microbiome operate synergistically, modulating host immune function and shaping the microbiome. Next generation molecular sequencing methodologies in tandem with modeling complex communities allow insights into the role of the microbiome in health and disease states. Infection-related disease states in which dysbiosis is integral include late-onset sepsis (LOS) and necrotizing enterocolitis (NEC), which still cause deaths and morbidity. Understanding microbiomic interactions may lead to alternative prevention, monitoring or treatment strategies, and modulation of long-term health outcomes especially in the preterm population. Recent studies have advanced understanding of the microbiome in NEC and LOS.

RECENT FINDINGS

Mechanisms of host-microbiome interaction have been demonstrated. Patterns of microbiomic change in association with NEC and LOS have been observed, with community changes dominated by Proteobacteria and Firmicutes appearing to precede NEC, and very early microbiomic signatures influencing LOS. Data on viral and fungal elements are emerging.

SUMMARY

Greater understanding of the neonatal bowel microbiome may allow tailored clinical practice and therapeutic intervention. Data handling and interpretation is challenging. Mechanistic studies of clinical interventions that affect the gut microbiome are important next steps.

The human intestinal microbiome at extreme ages of life. Dietary intervention as a way to counteract alterations

The intestinal microbiome is defined as the assembly of genomes from microorganisms inhabiting the gut. This microbial ecosystem regulates important functions of the host and its correct composition and functionality is essential for a “healthy status.” Metagenomic studies have highlighted variations of the intestinal microbiota as a function of age and diet. Colonization of the infant gut starts at birth and is influenced by feeding habits (formula vs. breast-feeding), birth mode and antibiotic exposure. The intestinal microbiota of full-term vaginally delivered breast-fed infants is considered the gold-standard, representing the reference for studies of alterations in other pediatric populations. At 2–3 years of age, the intestinal microbiota reaches a composition similar to adults, remaining without noticeable variations until senescence, when microbial instability and changes reappear. Here we summarize the current knowledge on intestinal microbiota alterations at extreme stages of life and tools for designing differentiated nutritional strategies by the use of probiotics, prebiotics and specific nutrients in order to restore a balanced microbiota and to improve immune and nutritional status.

Understanding heterogeneity among elderly consumers: an evaluation of segmentation approaches in the functional food market

It is beneficial for both the public health community and the food industry to meet nutritional needs of elderly consumers through product formats that they want. The heterogeneity of the elderly market poses a challenge, however, and calls for market segmentation. Although many researchers have proposed ways to segment the elderly consumer population, the elderly food market has received surprisingly little attention in this respect. Therefore, the present paper reviewed eight potential segmentation bases on their appropriateness in the context of functional foods aimed at the elderly: cognitive age, life course, time perspective, demographics, general food beliefs, food choice motives, product attributes and benefits sought, and past purchase. Each of the segmentation bases had strengths as well as weaknesses regarding seven evaluation criteria. Given that both product design and communication are useful tools to increase the appeal of functional foods, we argue that elderly consumers in this market may best be segmented using a preference-based segmentation base that is predictive of behaviour (for example, attributes and benefits sought), combined with a characteristics-based segmentation base that describes consumer characteristics (for example, demographics). In the end, the effectiveness of (combinations of) segmentation bases for elderly consumers in the functional food market remains an empirical matter. We hope that the present review stimulates further empirical research that substantiates the ideas presented in this paper.

In vitro evaluation of the impact of human background microbiota on the response to Bifidobacterium strains and fructo-oligosaccharides

The microbial colonisation of the infant gut begins immediately after birth and is essential for the development of the intestine, the immune system and later well-being. Important differences have been reported in the characteristics of such microbiota in different infant population groups. In the present study, we employed an in vitro faecal batch culture model using faeces from different human population groups (adults and full-term breast-fed, full-term formula-fed and preterm infants) to determine the influence that the addition of four bifidobacterial strains and fructo-oligosaccharides (FOS) exerts on the profile of SCFA measured by GC as well as on the levels of some relevant intestinal microbial groups by quantitative PCR during incubation. Differences were found in the levels of SCFA and intestinal microbial groups in the faecal cultures depending on the human group origin of the faecal samples (P< 0·05), this being a predominant factor, compared with bifidobacteria or FOS added, in determining microbiota dynamics. These results exhibit the importance of the initial characteristics of the basal intestinal microbiota in the effect exerted by bifidobacteria or FOS that are added and highlight the need to design probiotics targeting specific human population groups.