The Impact of Overnight Active Temperature Regulation on Gut Microbiome, Inflammation, and Circadian Rhythm.

NCT07848594 | Recruiting

• 1 other identifier: 17646
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

This study examines whether two continuous weeks of overnight active temperature regulation (via the Eight Sleep Pod) use affects gut microbiome composition, inflammation, and the body's daily temperature and blood pressure rhythms in postmenopausal women and age-matched men with self-reported poor sleep.

Conditions

Poor Sleep Quality; Gut Microbiome; Gut Health; Inflammation; Circadian Rhythm; Circadian Clocks; Gut Microbiota; Women's Health; Gut-Brain Axis; Blood Pressure; Systemic Inflammatory Response

Keywords

Gut Microbiome; Systemic Inflammation; Circadian Rhythm; Sleep Quality; Blood Pressure; Core Temperature; Poor Sleep; Postmenopausal; Active Temperature Regulation; Blood Pressure Rhythm; Gut Health; Gut Flora

Outcome Measures

Primary Outcomes (2)

• Gut Microbiome Composition

  alpha diversity: Shannon Index, beta diversity: Bray-Curtis, F/B ratio, genus-level abundance, SCFA concentrations

  Preparation Period, End of Condition, End of Condition 2 (~5 weeks)

• Systemic Inflammation (blood panel)

  hsCRP levels

  Preparation Period, End of Condition, End of Condition 2 (~5 weeks)

Secondary Outcomes (6)

• Circadian Rhythm of Core Body Temperature

  Participants will ingest one capsule on Night 11 (second week of Pod ON condition) and Night 28 (second week of Pod OFF condition) 60 minutes before their normal bedtime. These are to evaluate the core body temperature between ON and OFF conditions.

• Circadian Rhythm of Blood Pressure Rhythms

  24-hour BP: Night -1 (Prep), Nights 5 & 12 (Pod ON), and Nights 22 & 29 (Pod OFF). Single-point BP (takes ~1-2 minutes): Night 11 PM & Night 12 AM (Pod ON), and Night 28 PM & Night 29 AM (Pod OFF). No BP readings occur during the 3-day washout period.

• Objective Sleep Metrics: sleep staging, wakefulness after sleep onset and sleep onset latency (minutes)

  Objective sleep metrics are collected for the entire duration of the study (5-6 weeks total). The primary comparison for this outcome is objective sleep metrics (sleep staging, WASO, and sleep onset latency) between Pod ON and Pod OFF conditions.

• Objective sleep metrics: Sleep efficiency (overall %)

  Pod and biometric tracking smart ring data are collected for the entire duration of the study (5-6 weeks). The primary comparison for this outcome is objective sleep metrics (sleep efficiency, %) between Pod ON and Pod OFF conditions.

• Objective sleep metrics: Nighttime Respiratory Rate (RR)

  The Pod data and biometric tracking smart ring are collected for the entire duration of the study, for five weeks. The primary comparison for this outcome is objective sleep metrics (RR and BrPM) between Pod ON and Pod OFF conditions.

Other Outcomes (4)

• Wellbeing will be assessed by the World Health Organization Well-Being Index (WHO-5).

  Baseline score (%) during 5-day Preparatory Period (by Night 0); Pod ON at Night 14; Pod OFF at Night 31. Baseline may be completed anytime during Prep period. Pod ON/OFF scores reflect well-being over the prior 2 weeks. No WHO-5 during 3-day washout.

• Quality of life, including physical, mental and social health, will be assessed with the Patient-Reported Outcomes Measurement Information System (PROMIS) survey, a standardized and validated assessment.

  Baseline score during 5-day Preparatory period (by Night 0); Pod ON at Night 14; Pod OFF at Night 31. Baseline may be completed anytime during Prep period. Pod ON/OFF scores reflect quality of life over the prior 2 weeks. No PROMIS during 3-day washout.

• Menopausal symptom severity will be assessed for female participants with the Menopause Rating Scale (MRS),a validated questionnaire designed to assess the severity of menopausal symptoms.

  Baseline score during 5-day Preparatory period (by Night 0); Pod ON at Night 14; Pod OFF at Night 31. Baseline may be completed anytime during Prep period. Pod ON/OFF scores reflect well-being over the prior 2 weeks. No MRS during 3-day washout.

Study Arms (1)

Overnight Active Temperature Regulation ON and then OFF

EXPERIMENTAL

All participants undergo Condition 1 (ATR ON, 2 weeks - 14 nights) followed by washout and Condition 2 (ATR OFF, 2 weeks - 14 nights).

Device: Overnight Active Temperature Regulation: Eight Sleep Pod System

Interventions

Overnight Active Temperature Regulation: Eight Sleep Pod System DEVICE

Water-perfused mattress cover actively regulating temperature overnight, temperature will be ON during Condition 1 and OFF during Condition 2.

Overnight Active Temperature Regulation ON and then OFF

Eligibility Criteria

• Age: 45 Years+
• Gender Eligibility Details: There are two cohorts: Cohort A and Cohort B have all the same Inclusion and Exclusion Criteria except for brief Cohort specific criteria indicated in the criteria
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• years of age or older
• Self-reported poor sleep quality: PSQI score greater than 5
• Within 1.5 hours driving of the Greater Boston area
• Have never used an Eight Sleep Pod (or similar device) ever
• No MRI scheduled during the study period or within 1 week after study conclusion
• No acute illness, injury, or dental procedure/cleaning within 3 months prior to study start
• Non-smoker or previous infrequent (\<1 weekly) smoker who has ceased at least 3 months prior to study start
• Predictable bowel movements: at least 3 weekly and no more than 3 daily bowel movements
• Able to drive or be transported to a local lab facility at least three total times for blood panels
• Willing to complete 3 blood panels (3-4 tubes of blood collected at each draw): no strong aversion to needles
• Able to swallow a pill/capsule (approximately the size of the standard vitamin capsule) for internal core temperature monitoring
• Stable diet for a minimum of 3 months prior to enrollment, with no planned major dietary changes during the study period
• Stable medication regimen: no medication type or dose changes within 3 months prior to study start, and no plans to change medications during the study. This includes long-term -medication like antidepressants, statins, hormones, antihypertensives, or levothyroxine.
• Stable exercise routine for a minimum of 3 months prior to study start, with no planned changes to this routine
• Stable dietary supplement routine for a minimum of 3 months prior to the study start: includes probiotics, synbiotics, supplemental SCFA's

You may not qualify if:

• Currently taking any of the following medications/supplements or have changed use status (using to not using or vice versa) within 3 months before study start.
• Antibiotics (any kind), including one-time or short-term antibiotic use
• Corticosteroids (oral or injection only, topical preparations included):
• Prednisone
• Prednisolone
• Dexamethasone
• Hydrocortisone
• Methylprednisolone (Medrol)
• Budesonide
• Betamethasone
• Anti-TNF-α medications (biologics for arthritis, Crohn's disease, psoriasis, or other immune/inflammatory conditions):
• Adalimumab (Humira)
• Etanercept (Enbrel)
• Infliximab (Remicade)
• Certolizumab (Cimzia)

Sponsors & Collaborators

• Eight Sleep Inc.: lead
• Boston University: collaborator

Study Sites (1)

Eight Sleep

Newton Center, Massachusetts, 02459, United States

RECRUITING

Related Links

• Recruitment Survey

MeSH Terms

Conditions

Inflammation; Sleep Initiation and Maintenance Disorders

Condition Hierarchy (Ancestors)

Pathologic Processes; Pathological Conditions, Signs and Symptoms; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Mental Disorders

Study Officials

• David He, PhD

  Vice President of Research and Development,

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Amelia Mitchell, BS

CONTACT

203-931-5606; amelia.mitchell@eightsleep.com

Megan Holm, MS

CONTACT

(617) 237-6054‬; megan@eightsleep.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Masking Details: Partial Blinding of some of the study team.
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Within-subject/ single group model; Preparation Period (5 nights) -\> Condition 1 Pod ATR ON (2 weeks) and Condition 2 Pod ATR OFF (2 weeks), separated by a 3 day washout period

Study Record Dates

• First Submitted: September 16, 2026
• First Posted: September 30, 2026
• Study Start: October 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: September 30, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)