Lactobacillus delbrueckii reduces anxiety-like behavior in zebrafish through a gut microbiome - brain crosstalk.

Certain bacteria possess the ability to reduce anxiety- and stress-related behaviors through the gut microbiome-brain axis. Such bacteria are called psychobiotics, and can be used to improve mood and cognition. However, only a few bacteria have been characterized as psychobiotics, and their exact mechanism of action remains unclear. Hence, in this study we analyzed three different species under the Lactobacillacea family, namely, Lactobacillus delbrueckii, Lacticaseibacillus casei, and Lacticaseibacillus paracasei for their potential psychobiotic activities. L. delbrueckii treatment reduced anxiety-like behavior and increased brain and gut glutamic acid decarboxylase (gad) gene expression in zebrafish. It also altered zebrafish gut microbial community as determined by PCR-DGGE and 16S rRNA-based metagenomics analysis. Overall, this paper showed that L. delbrueckii but not L. paracasei and L. casei, induced a consistent improvement in anxiety-like behavior in zebrafish, implicating its potential role as a psychobiotic to reduce anxiety. This article is part of the Special Issue on 'Microbiome & the Brain: Mechanisms & Maladies'.

A Pilot Cancer-Phenome Biobanking System in a Low-Resource Southeast Asian Setting: The Philippine General Hospital Biobank Experience.

Biobanking has become an indispensable tool for translational research and health innovations. While the field of biobanking has progressed and evolved globally, biobanking in developing Association of Southeast Asian Nations (ASEAN) countries such as the Philippines remains underrepresented because of several challenges often encountered in these low- and middle-income countries. Recently, the Philippine government has undertaken enormous efforts to advancing research and development in the country, and one of the current research pursuits is the establishment of biobanks, with the hope of attaining more discoveries and innovations in the future. Given that cancer remains a leading cause of death in the Philippines, the Philippine government supported the establishment of a cancer biobank at the Philippine General Hospital (PGH). In this study, we present a specific use case of biobanking activity at the PGH Biobank, to build a cohort of biospecimens from Filipino patients with breast, endometrial, and ovarian cancer. This initiative is part of a biomonitoring study (1) to assess environmental exposures and possible risk factors in the Philippine population and (2) to develop a system of culturing human cells from Filipino patients for subsequent in vitro studies. We discuss issues faced and the solutions developed during the implementation of the biobank. Strong research collaboration, a funding source, basic infrastructure, and appropriate technology helped initiate this pilot biobank in the Philippines. Overall, the experiences of establishing the PGH Biobank may help other institutions in low-resource countries to set up cancer biobanks.

Resilience of the prokaryotic microbial community of Acropora digitifera to elevated temperature.

The coral is a holobiont formed by the close interaction between the coral animal and a diverse community of microorganisms, including dinoflagellates, bacteria, archaea, fungi, and viruses. The prokaryotic symbionts of corals are important for host fitness but are also highly sensitive to changes in the environment. In this study, we used 16S ribosomal RNA (rRNA) sequencing to examine the response of the microbial community associated with the coral, Acropora digitifera, to elevated temperature. The A. digitifera microbial community is dominated by operational taxonomic unit (OTUs) affiliated with classes Alphaproteobacteria and Gammaproteobacteria. The prokaryotic community in the coral tissue is distinct from that of the mucus and the surrounding seawater. Remarkably, the overall microbial community structure of A. digitifera remained stable for 10 days of continuous exptosure at 32°C compared to corals maintained at 27°C. However, the elevated temperature regime resulted in a decrease in the abundance of OTUs affiliated with certain groups of bacteria, such as order Rhodobacterales. On the other hand, some OTUs affiliated with the orders Alteromonadales, Vibrionales, and Flavobacteriales, which are often associated with diseased and stressed corals, increased in abundance. Thus, while the A. digitifera bacterial community structure appears resilient to higher temperature, prolonged exposure and intensified stress results in changes in the abundance of specific microbial community members that may affect the overall metabolic state and health of the coral holobiont.