Opioid-induced dysbiosis of maternal gut microbiota during gestation alters offspring gut microbiota and pain sensitivity

ABSTRACT

There has been a rapid increase in neonates born with a history of prenatal opioid exposure. How prenatal opioid exposure affects pain sensitivity in offspring is of interest, as this may perpetuate the opioid epidemic. While few studies have reported hypersensitivity to thermal pain, potential mechanisms have not been described. This study posits that alterations in the gut microbiome may underly hypersensitivity to pain in prenatally methadone-exposed 3-week-old male offspring, which were generated using a mouse model of prenatal methadone exposure. Fecal samples collected from dams and their offspring were subjected to 16s rRNA sequencing. Thermal and mechanical pain were assessed using the tail flick and Von Frey assays. Transcriptomic changes in whole brain samples of opioid or saline-exposed offspring were investigated using RNA-sequencing, and midbrain sections from these animals were subjected to qPCR profiling of genes related to neuropathic and inflammatory pain pathways. Prenatal methadone exposure increased sensitivity to thermal and mechanical pain and elevated serum levels of IL-17a. Taxonomical analysis revealed that prenatal methadone exposure resulted in significant alterations in fecal gut microbiota composition, including depletion of Lactobacillus, Bifidobacterium, and Lachnospiracea sp and increased relative abundance of Akkermansia, Clostridium sensu stricto 1, and Lachnoclostridium. Supplementation of the probiotic VSL#3 in dams rescued hypersensitivity to thermal and mechanical pain in prenatally methadone-exposed offspring. Similarly, cross-fostering prenatally methadone-exposed offspring to control dams also attenuated hypersensitivity to thermal pain in opioid-exposed offspring. Modulation of the maternal and neonatal gut microbiome with probiotics resulted in transcriptional changes in genes related to neuropathic and immune-related signaling in whole brain and midbrain samples of prenatally methadone-exposed offspring. Together, our work provides compelling evidence of the gut-brain-axis in mediating pain sensitivity in prenatally opioid-exposed offspring.

KEYWORDS:

• Prenatal opioid exposure
• methadone
• probiotics
• microbiome
• brain transcriptome
• thermal pain sensitivity

List of abbreviations

POE	=	prenatal opioid exposure
FMM	=	fostered to methadone mothers
FCM	=	fostered to saline-treated (control) mothers
CTRL	=	prenatally saline-exposed (control) offspring
MET	=	prenatally methadone-exposed offspring
MET + PRO	=	MET whose mothers were administered VSL#3 probiotics
CTRL+ PRO	=	CTRL whose mothers were administered VSL#3 probiotics

Acknowledgments

We thank Valerie Gramling from the University of Miami Writing Center for help with the editing of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors’ contributions

YA conceptualized this project, and coordinated the experimental design, conduct, and data acquisition and analysis of this project. YA generated mouse lines and wrote and revised the majority of the manuscript. YA, SS, IC, and JM performed experiments, analyzed data and/or contributed to the writing of this manuscript. PS and JT performed data analyses. This research was supported by grants from SR. All authors reviewed the results, commented on the manuscript, and approved the final version of the manuscript.

Availability of data and materials

All data generated or analyzed during this study are included in this published article and its supplementary information files. Accompanying metadata is available using accession number S-BSST1226 at the online data repository: https://www.ebi.ac.uk/biostudies/studies/S-BSST122

Ethics approval and consent to participate

This study was approved by the Institutional Animal Care and Use Committee policies at the University of Miami and adhered to all ethical guidelines related to the care of laboratory animals. (Protocol: 20–100).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/19490976.2023.2292224

Additional information

Funding

National Institutes of Health, Grant/Award Numbers: F31DA053795, R01 DA050542, R01 DA047089, R01 DA043252 and R01 DA044582.