Ecological linkages between biotechnologically relevant autochthonous microorganisms and phenolic compounds in sugar apple fruit (Annona squamosa L.).

Our study investigated the potential of Annona squamosa (L.) fruit as a reservoir of yeasts and lactic acid bacteria having biotechnological implications, and phenolics capable of modifying the ecology of microbial consortia. Only a single species of lactic acid bacteria (Enterococcus faecalis) was identified, while Annona fruit seemed to be a preferred niche for yeasts (Saccharomyces cerevisiae, Hanseniaspora uvarum), which were differentially distributed in the fruit. In order to identify ecological implications for inherent phenolics, the antimicrobial potential of water- and methanol/water-soluble extracts from peel and pulp was studied. Pulp extracts did not show any antimicrobial activity against the microbial indicators, while some Gram-positive bacteria (Staphylococcus aureus, Staphylococcus saprophyticus, Listeria monocytogenes, Bacillus megaterium) were susceptible to peel extracts. Among lactic acid bacteria used as indicators, only Lactococcus lactis and Weissella cibaria were inhibited. The chemical profiling of methanol/water-soluble phenolics from Annona peel reported a full panel of 41 phenolics, mainly procyanidins and catechin derivatives. The antimicrobial activity was associated to specific compounds (procyanidin dimer type B [isomer 1], rutin [isomer 2], catechin diglucopyranoside), in addition to unidentified catechin derivatives. E. faecalis, which was detected in the epiphytic microbiota, was well adapted to the phenolics from the peel. Peel phenolics had a growth-promoting effect toward the autochthonous yeasts S. cerevisiae and H. uvarum.

Effects of Saccharomyces boulardii Supplementation on Nutritional Status, Fecal Parameters, Microbiota, and Mycobiota in Breeding Adult Dogs.

The aim of this study was to evaluate the effect of the administration of Saccharomyces boulardii on the nutritional, immunological, inflammatory, and stress status and on the composition of the gut microbiota and mycobiota in healthy adult dogs. A total of 25 American Staffordshire Terrier dogs were selected and randomly assigned to two groups: control (CTR, n = 12) and treated (TRT, n = 13) groups. No significant differences were found between the two groups regarding body weight, body condition score, and fecal score. No significant differences in microbiota/mycobiota, short chain fatty acids, indole/skatole, histamine, zonulin, or lactoferrin were detected. Indeed, supplementation with S. boulardii significantly decreased fecal calprotectin Immunoglobulin A, indicating an improvement in the gut well-being. Interestingly, fecal cortisol significantly decreased in dogs belonging to the TRT group compared to the CTR, suggesting both an improvement of the intestinal status and a reduction of stress, a common condition affecting animals managed in a breeding environment.

Effects of Feeding Dried Fruit Pomaces as Additional Fibre-Phenolic Compound on Meat Quality, Blood Chemistry and Redox Status of Broilers.

The present study investigated the effects of apple (A), blackcurrant (B) and strawberry (S) dried pomaces on meat quality, blood chemistry and redox status of broiler chickens. A total of 480 Ross-308 male broilers were divided into 8 dietary treatments containing 3% and 6% of cellulose preparation (C), A, B or S. Six birds/group were slaughtered at 35 days of age and blood samples were collected. Carcass traits and meat quality were determined on the Pectoralis major muscles, recording nonsignificant differences. Antioxidant activity was evaluated in serum, liver and breast muscle. In serum, fruit pomaces lowered triglycerides, creatinine and atherogenic index (p < 0.05). Regarding redox status, in serum, ACW (antioxidant capacity of water-soluble substances) and ACL (antioxidant capacity of lipid-soluble substances) were greater in A (p < 0.001). In breast, ACW and ACL were higher in B and S compared to C (p < 0.05). In liver, ACL was greater in B and S compared to C (p < 0.001) and in higher dosage compared to low (p = 0.036). GSSG (oxidized glutathione) concentration was lower in A, whereas A, B and S presented a higher GSH (reduced glutathione)/GSSG ratio. The results showed that fruit pomaces could represent promising feed ingredients for broilers, improving serum, meat and tissue antioxidant parameters.

Dried fruit pomace inclusion in poultry diet: growth performance, intestinal morphology and physiology.

BACKGROUND: Fruit pomaces are by-products rich in polyphenol compounds and dietary fiber. They seem to play an important role in regulating the gut microbiota, morphology and physiology. The aim of this study was to assess whether apple (A), blackurrant (B) or strawberry (S) pomaces could be suitable ingredients in broiler diets and their effect on gut health. A total of 480 male broilers were randomly allotted to 8 dietary treatments with lower (3%-L) or higher (6%-H) dietary fiber content: two control groups (CL/CH), two A diets (AL/AH), two B diets (BL/BH), two S diets (SL/SH). Diet and fruit pomaces were chemically analyzed to assess polyphenol concentration and fibre fraction content. After the evaluation of growth performance, 6 birds/group were slaughtered at 35 days of age. Morphometric and histopathological investigations were performed on duodenum, jejunum and ileum. Excreta were collected to perform microbiota evaluation by 16S DNA sequencing. Weight, viscosity, enzymatic activity, short chain fatty acid (SCFAs) and ammonia concentration were determined in ileum and/or ceca content. RESULTS: A pomace and A diets showed the lowest polyphenol content and the highest content of soluble fibre fraction. No significant differences were observed for growth performance, gut morphometry and histopathology (P > 0.05). Dietary fruit pomace inclusion increased the weight of ileum and ceca and the ileum digesta viscosity (P < 0.05). In the ileum, A and S groups showed lower bacterial α-glucosidase activity than C groups. Moreover, small intestine SCFAs concentration was higher in fruit pomaces diets (P < 0.05). In ceca, B and S groups showed lower ammonia concentration and higher SCFAs than C. Dietary treatments also influenced the activity of α-glucosidase, α-galactosidase, ß-galactosidase ß-glucuronidase and xylase. Regarding microbiota, at phylum level, Firmicutes were differentially abundant across treatment (maximum for C and minimum in S, FDR > 0.05). At genus level, an increase of Weissella in AH and Erwinia in S/B diets, as well as a decrease of Lactobacillus in all fruit pomace groups were recorded (P < 0.05). CONCLUSIONS: Fruit pomaces could be suitable ingredients in poultry nutrition even if further studies are needed to better understand which doses is more recommended to avoid negative effects on gut microbiota.

Gut microbiota composition after diet and probiotics in overweight breast cancer survivors: a randomized open-label pilot intervention trial.

OBJECTIVES: Breast cancer (BC) is the most diagnosed cancer in women. Increasing survival rates shift attention to preventive strategies. Obesity and intestinal microbiota composition may be associated with BC. A Mediterranean diet (MD) proved to be protective. The aim of this study was to assess the efficacy of probiotics in addition to an MD versus diet alone in influencing gut microbiota and metabolic profile in overweight BC survivors. METHODS: A total of 34 BC survivors were randomly assigned to an MD for 4 mo plus 1 sachet/d of probiotics (Bifidobacterium longum BB536, Lactobacillus rhamnosus HN001) for the first 2 mo (intervention group, n = 16) or an MD alone for 4 mo (control group, n = 18). Anthropometric and nutritional assessments, adherence to the MD, compliance with physical activity, and metabolic parameters dosage were performed at baseline (T0), at 2 mo (T2), and at 4 mo (T4). Intestinal microbiota analysis was performed at T0 and T2. RESULTS: After 2 mo of probiotic administration the number of bacterial species (P = 0.01) and the bacterial diversity assessed with the Chao1 index (P = 0.004) significantly increased; no significant variations were detected after diet alone. The Bacteroidetes-to-Firmicutes ratio significantly decreased in the intervention group and increased in controls (P = 0.004). Significant reductions of body weight, body mass index, fasting glucose, and homeostasis model assessment of insulin resistance were identified at T4 in both groups; in the intervention group waist circumference (P = 0.012), waist-to-hip ratio (P = 0.045), and fasting insulin (P = 0.017) also significantly decreased. CONCLUSIONS: Probiotics in addition to an MD positively influence gut microbiota and improve metabolic and anthropometric parameters compared with an MD alone.

Antilisterial Effect and Influence on Listeria monocytogenes Gene Expression of Enterocin or Enterococcus faecalis in Sliced Dry-Cured Ham Stored at 7°C.

In this study, we focused on the effect of an enterocin or an Enterococcus faecalis strain added onto sliced dry-cured ham that was artificially inoculated with Listeria monocytogenes and stored at 7°C. The population of L. monocytogenes and the expression of five genes were monitored throughout the storage period. A persistent and a nonpersistent strain were tested, and both were influenced by the presence of the enterocin; both populations were reduced by more than 2 Log CFU/g after 14 days compared with the control, noninoculated ham. The presence of E. faecalis, a bacteriocin-producing lactic acid bacterium, had a less pronounced effect on the viable counts for both strains. Concerning gene expression, a common trend observed for both strains in the presence of enterocin was the down-regulation of genes tested after 30 min of storage at 7°C. For the remainder of the storage period, the expression fluctuated but was mostly reduced. Similarly, the presence of E. faecalis led to an overall down-regulation of genes. The effect on gene expression of both enterocin and E. faecalis was more pronounced on the nonpersistent L. monocytogenes strain. Although the potential of a bacteriocin and a bacteriocin-producing microorganism to control L. monocytogenes was confirmed, this study highlights that gene expression may be influenced and needs to be evaluated when considering such biopreservation interventions.

Effect of Atmospheric Pressure Plasma on Listeria monocytogenes Attached to Abiotic Surfaces.

Listeria monocytogenes can be introduced into food processing plants via raw material of animal or plant origin and can establish endemic populations through formation of biofilms. Biofilms are a continuous source of contamination for food products, and L. monocytogenes cells in biofilms are more resistant to stress and sanitizing agents than are planktonic cells. The use of gas-discharge plasmas may offer a feasible alternative to conventional sanitization methods. Plasmas are a mixture of charged particles, chemically reactive species, and UV radiation and can be used to destroy microorganisms. The purpose of this study was to measure the effectiveness of cold atmospheric pressure plasma (APP) treatments against bacteria attached to a solid surface and to evaluate the individual susceptibility of various L. monocytogenes strains. Attention was focused on the state of the cells after treatment, combining detection by viable counts and quantitative PCR (qPCR). Most of the culturable cells were inactivated after APP treatment, but the qPCR assay targeting the 16S rRNA revealed the presence of injured cells or their entrance into the viable but nonculturable state. These results were at least partly confirmed by a resuscitation experiment. After APP treatment, L. monocytogenes cell suspensions were incubated in brain heart infusion broth; some cells grew in the medium and therefore had survived the treatment. An understanding of the effects of APP on L. monocytogenes can inform the development of sanitation programs incorporating APP for pathogen removal. Methods other than those based of the culturability of the cells should be used to monitor pathogens in food processing plants because cultivation alone may underestimate the actual microbial load.