Long Exposure to a Diet Supplemented with Antioxidant and Anti-Inflammatory Probiotics Improves Sperm Quality and Progeny Survival in the Zebrafish Model.

The aim of the present experiment is to study the effects of oral ingestion of a mixture of two probiotic bacteria on sperm quality and progenies. Three homogeneous groups of juvenile zebrafish were created. Once having reached adulthood (3 months postfertilization; mpf), each group received different feeding regimens: a standard diet (control), a maltodextrin-supplemented diet (vehicle control), or a probiotic-supplemented diet (a mixture (1:1) of Lactobacillus rhamnosus CECT8361 and Bifidobacterium longum CECT7347). The feeding regime lasted 4.5 months. Growth parameters (weight and length) were determined at 3, 5, and 7.5 mpf. Sperm motility was evaluated using computer-assisted sperm analysis at 5 and 7.5 mpf. Progeny survival, hatching rate, and malformation rate were also evaluated. Results showed that probiotic-supplemented diet improved growth parameters compared with the standard diet. The highest percentage of motile spermatozoa was reported in the probiotic-fed group. Concomitantly, the percentage of fast sperm subpopulation was significantly lower in samples derived from control males. Furthermore, there was a significant difference in progeny survival between the probiotic-fed group and the control group at three developmental times (24 hours postfertilization (hpf), 5 days postfertilization (dpf) and 7 dpf). In conclusion, in zebrafish, prolonged ingestion of a mixture of Lactobacillus rhamnosus CECT8361 and Bifidobacterium longum CECT7347 has positive effects on growth, sperm quality, and progeny survival.

Diet Supplemented with Antioxidant and Anti-Inflammatory Probiotics Improves Sperm Quality after Only One Spermatogenic Cycle in Zebrafish Model.

Infertility is a medical concern worldwide and could also have economic consequences in farmed animals. Developing an efficient diet supplement with immediate effects on sperm quality is a promising tool for human reproduction and for domesticated animal species. This study aims at elucidating the effect of a short-time probiotic supplementation consisting of a mixture of two probiotic bacteria with proven antioxidant and anti-inflammatory activities on zebrafish sperm quality and male behavior. For this purpose, three homogeneous groups of males in terms of motility (<60%) were established. The control group was fed with a normal standard diet. The other received supplements: One group (vehicle control) was fed with maltodextrin and the other received a probiotic preparation based on a mixture (1:1) of Lactobacillus rhamnosus CECT8361 and Bifidobacterium longum CECT7347. The feeding regime was 21 days corresponding with a single spermatogenesis in zebrafish. The preparation did not modify animal weight, positively affected the number of fluent males, increased sperm concentration, total motility, progressive motility, and fast spermatozoa subpopulations. Moreover, the animals fed with the supplement showed different behavior patterns compared to control groups. Our results suggest a diet-related modulation on the exploration activity indicating a lower stress-like conduct. The studied formulation described here should be considered as advantageous in male reproductive biotechnology.

Circulating small non-coding RNAs provide new insights into vitamin K nutrition and reproductive physiology in teleost fish.

BACKGROUND: Vitamin K (VK) is a fat-soluble vitamin known for its essential role in blood coagulation, but also on other biological processes (e.g. reproduction, brain and bone development) have been recently suggested. Nevertheless, the molecular mechanisms behind its particular function on reproduction are not yet fully understood. METHODS: The potential role of VK on reproduction through nutritional supplementation in Senegalese sole (Solea senegalensis) was assessed by gonadal maturation and 11-ketosterone, testosterone and estriol plasma levels when fed with control or VK supplemented (1250 mg kg-1 of VK1) diets along a six month trial. At the end, sperm production and quality (viability and DNA fragmentation) were evaluated. Circulating small non-coding RNAs (sncRNAs) in blood plasma from males were also studied through RNA-Seq. RESULTS: Fish fed with dietary VK supplementation had increased testosterone levels and lower sperm DNA fragmentation. SncRNAs from blood plasma were found differentially expressed when nutritional and sperm quality conditions were compared. PiR-675//676//4794//5462 and piR-74614 were found up-regulated in males fed with dietary VK supplementation. Let-7g, let-7e(18nt), let-7a-1, let-7a-3//7a-2//7a-1, let-7e(23nt) and piR-675//676//4794//5462 were found to be up-regulated and miR-146a and miR-146a-1//146a-2//146a-3 down-regulated when fish with low and high sperm DNA fragmentation were compared. Bioinformatic analyses of predicted mRNAs targeted by sncRNAs revealed the potential underlying pathways. CONCLUSIONS: VK supplementation improves fish gonad maturation and sperm quality, suggesting an unexpected and complex regulation of the nutritional status and reproductive performance through circulating sncRNAs. GENERAL SIGNIFICANCE: The use of circulating sncRNAs as reliable and less-invasive physiological biomarkers in fish nutrition and reproduction has been unveiled.