The influence of breast milk and infant formulae hydrolysates on bacterial adhesion and Caco-2 cells functioning.

The aim of the study was to determine the concentration of BCM7 in human milk and infant formulae (IF) before and after eznymatic hydrolysis, and to evaluate the effect of obtained hydrolysates on interleukin-8 (IL-8) secretion and on proliferation of enterocytes in the in vitro model (Caco-2 cells). This study evaluates also the effect of hydrolysates on the adhesion of intestinal microbiota isolated from faeces of both healthy (H) and allergic (A) infants. In the study we investigated breast milk delivered by mothers of healthy ('healthy milk'; HM) and allergic ('allergic milk'; AM) infants. Three infant formulae were investigated: from hydrolysed cow casein (IF1), from hydrolysed cow whey (IF2) and from whole cow milk (IF3). Intestinal bacteria: Bifidobacterium, lactic acid bacteria, Enterobacteriaceae, Clostridium and Enterococcus were isolated from faeces of five healthy and five allergic infants. Mixtures of bacterial isolates and bacteria adhering to Caco-2 cells were characterised qualitatively with PCR-DGGE, and quantitavely with FISH. Concentration of BCM7 in breast milk and infant formulae was 1.6 to 8.9 times higher after enzymatic hydrolysis in comparison to undigested samples. The presence of this peptide resulted in alteration of intestinal epithelial proliferation and increase in secretion of IL-8. The quantitative profile of adherred bacteria applied as a mix of all isolates from healthy infants (H-MIX) was unchanged in the presence of HM hydrolysate and was modulated (increased number of beneficial Bifidobacterium and reduced commensal Enterobacteriaceae) in the presence of all IF hydrolysates. The presence of IF hydrolysates affected the profile of adhering isolates obtained from allergic infants (A-MIX) and reduced the adhesion of Enterobacteriaceae; the IF2 and IF3 hydrolysates decreased also the total number of adhering bacteria (TBN). However, a stimulating effect of AM hydrolysate on A-MIX adhesion (increased TBN) was observed.

The effect of hydrolysates of proteins from rice milk on the physiological response of enterocytes and on the adhesion of bacteria from healthy and allergic people - an in vitro study.

Designing an optimal diet requires knowledge of the biological activity of food products, particularly in relation to people with food allergies. The hypothesis, which constitutes the basis of this thesis, states that the peptides and glycopeptides released from proteins by enzymatic hydrolysis are able to change the quantity and quality of the human gastrointestinal ecosystem. Such substrates may interfere with adhesion to the intestinal epithelium microbiota and alter enterocytic metabolic activity. The aim of this study was to determine the effect of protein hydrolysates from rice milk substitute on gut epithelial cells and the intestinal microbiota of healthy people and ones suffering from an allergy to milk. The following experimental work applied systems that reflect the conditions occurring in the gastrointestinal tract.

The study on the impact of glycated pea proteins on human intestinal bacteria.

The traditionally perceived function of nutrition includes supplying the consumer with the appropriate quantity and quality of substrates. As nutritional substrates, proteins are prone to spontaneously occurring non-enzymatic glycosylation (glycation) which can alter their molecular structure, making them highly bioactive. Glycated food proteins are able to modify the bacterial intestinal ecosystem, which is of great importance for the optimal usage of nutrients and maintenance of both intestinal homeostasis and balanced health status of the consumer. This study aimed to determine the impact of glycated pea proteins on the intestinal bacteria from a healthy human. The analyses were conducted with the use of experimental batch-type simulator models imitating human intestinal conditions. The glycated pea proteins affected the growth of gut commensal bacteria, particularly lactobacilli and bifidobacteria, whose levels increased significantly. There was a corresponding shift in the bacterial metabolites with increased levels of the short chain fatty acids (SCFAs); acetate, propionate lactate and butyrate. Intestinal bacteria were able to utilize these pea proteins thus indicating that the energy encrypted in glycated pea proteins, partially inaccessible for gastric enzymes, may be salvaged by gut microbiota. Such changes in microbial composition may beneficially impact the intestinal environment and exert a health-promoting effect in humans.

Impact of glycated pea proteins on the activity of free-swimming and immobilised bacteria.

BACKGROUND: Glycation (non-enzymatic glycosylation), a spontaneously occurring process, is responsible for alteration of the structures and biological activities of proteins, making them highly active. Regrettably, information regarding the impact of glycated food proteins on intestinal bacteria still remains sparse. Pea seeds are considered to be a biological material of a high nutritional value, low content of anti-nutritional substances and proven health-promoting action and therefore they were used in this study. Since glycated pea proteins are proven to display a lowered susceptibility to the enzymatic digestion, their impact on the activity of both free-swimming and immobilised bacteria was studied. RESULTS: In vitro model systems were used to prove the stimulatory impact of glycated pea proteins on the proliferation rate and survival, as well as on the metabolic activity of free-swimming and immobilised bacteria. CONCLUSIONS: This phenomenon is of great importance because glycated food proteins are not only a source of nutrients and energy but also display new properties and increased biological activities. Additionally, they are able to modify the bacterial intestinal ecosystem, thus affecting the general health status of a consumer.

The impact of pea protein hydrolysates on bacterial physiological activity--an in vitro study.

So far, food proteins have been perceived hitherto purely as a source of nutrients indispensable for maintaining life. However, latest findings strongly indicate that food proteins may release biologically active peptides in a consequence of enzymatic degradation. Such hydrolysates may be used as food components in order to beneficially influence human health. Additionally, such modified peptides may affect the balance of bacteria inhabiting human gastrointestinal tract and thus bring about health complication of the host. Although pea seeds are of significant nutritional value due to their high contents of proteins, carbohydrates and fibre, they are also responsible for health inconveniences resulting from their susceptibility to digestion and occurrence of antinutritional as well as allergic compounds. The enzymatic degradation may pass over these nutritional obstacles by liberating hydrolysates empowered not only to exert their impact on the human physiology but also on bacterial intestinal ecosystem. Therefore, the aim of this study was to evaluate the influence of pea protein hydrolysates on bacteria typical for the small intestine. Pea protein hydrolysates have proved to diversely modulate physiological activity of bacteria existing in different states. The observed detrimental effect on planktonic bacteria was abolished in the case of bacteria immobilized to the solid surfaces, confirming the protective effect of biofilms. Additionally, Lactobacilli displayed adaptive properties enabling them to utilize pea protein hydrolysates regardless their state of existence.