About

Mallika S. Sarma, PhD, is a human biologist specializing in extreme environments. Her research focuses on human adaptation and acclimation to extreme or novel environments, including stress and resilience, energetic physiology, neuroendocrine systems, behavior, human variation and plasticity, and human biology in space. She is a Postdoctoral Research Fellow at the Translational Research Institute for Space Health (TRISH) and is affiliated with the Human Spaceflight Lab at Johns Hopkins School of Medicine.

Research topics

• Medicine
• Endocrinology
• Biology
• Ecology
• Pediatrics
• Psychology
• Developmental psychology
• Physical therapy
• Gerontology
• Demography

Selected publications

• Methodologic Opportunities for Space Health Research: Integrating Biological Anthropology Methods in Human Research for Precision Space Health and Medical Data

  Wilderness and Environmental Medicine · 2025-07-07 · 3 citations

  articleOpen access1st authorCorresponding

  As the field of health and medicine in space develops alongside the spaceflight research paradigm, there are methodologic opportunities to integrate data collection for research with providing precision and personalized healthcare. Specifically, existing field methods in biological anthropology developed and practiced in austere settings can be translated to spaceflight research and the development of healthcare infrastructure with implications for space medical practice. In our era of expanding spaceflight, data-collection methodologies should be flexible, agile, and accessible, paralleling innovative strategies by biological anthropology field researchers assessing human health, behavior, and well-being in austere terrestrial settings. Here we offer an introduction to the methodologic approaches and theoretical frameworks from biological anthropology, including operational insights from investigators working in the field, highlighting flexible mixed methods, low-tech solutions, dialectic engagement with participants, and iterative research protocols. These tools, when performed together with standardized approaches, can be beneficial and augment the advancement of spaceflight health and medicine.

  PublisherDOI

• Evaluating the Buffering Role of Perceived Social Support and Coping Resources Against the Adult Mental Health Impacts of COVID-19 Psychosocial Stress: A Cross-Sectional Study in South Africa

  Adversity and Resilience Science · 2024-07-10 · 3 citations

  articleOpen accessSenior author

  Abstract Growing evidence has highlighted the global mental health impacts of the COVID-19 pandemic and lockdown, particularly in societies with pre-existing socioeconomic adversities and public health concerns. Despite the sudden and prolonged nature of many psychosocial stressors during the pandemic, recent studies have shown that communities utilized several coping mechanisms to buffer the mental health consequences of COVID-related stress. This paper examines the extent to which coping resources and social support buffered against the mental health effects of COVID-19 psychosocial stress among adults in South Africa. Adult participants ( n = 117) completed an online survey during the second and third waves of the COVID-19 pandemic in South Africa (January–July 2021), which assessed experiences of stress, coping resources, social support, and four mental health outcomes: depression, anxiety, post-traumatic stress disorder, and bipolar disorder. Moderation analyses examined the potential buffering role of coping resources and social support against the mental health effects of COVID-19 stress. Adults reported elevated rates of psychiatric symptoms. Coping resources buffered against the poor mental health effects of COVID-19 psychosocial stress, whereas perceived social support did not significantly moderate the association between COVID-19 stress and adult mental health. These results suggest that adults in our sample utilized a variety of coping resources to protect their mental health against psychosocial stress experienced during the COVID-19 lockdown and pandemic in South Africa. Additionally, existing mental health conditions and strained social relationships may have attenuated the potential stress-buffering effect of perceived social support on adult mental health.

  PublisherOA PDFDOI

• BaYaka mothers balance childcare and subsistence tasks during collaborative foraging in Congo Basin

  bioRxiv (Cold Spring Harbor Laboratory) · 2024-01-24

  preprintOpen access

  ABSTRACT Across cultures, mothers face trade-offs between childcare and other labor. In hunter-gatherer societies, mothers face this choice on a daily basis when deciding either to take infants on foraging trips or to leave them with caregivers in the village. Yet, it remains unclear how the presence of infants in foraging groups constrains mothers’ mobility during foraging. Here, we present GPS, energy expenditure and food returns data of 359 foraging trips of 23 BaYaka mothers in the Republic of the Congo. We find that mothers spent more time on out-of-village foraging activities when they took infants along, compared to when they left infants behind. However, infant presence in foraging groups does not affect mothers’ travel distance, travel range, energy expenditure or food returns. Regardless of infant presence, women travel longer and further in a larger area when foraging in groups, compared to when foraging alone, especially in groups with more adults, females and both kin and non-kin. Our results suggest that BaYaka mothers develop ways to accommodate childcare with foraging activities by combining individual-level and group-level behavioural strategies. Our study highlights that group foraging may allow mothers with infants to maintain high mobility, which may have been a key to human range expansion.

  PublisherOA PDFDOI

• The human biology of spaceflight

  American Journal of Human Biology · 2024-02-09 · 10 citations

  articleOpen access1st authorCorresponding

  To expand the human exploration footprint and reach Mars in the 2030s, we must explore how humans survive and thrive in demanding, unusual, and novel ecologies (i.e., extreme environments). In the extreme conditions encountered during human spaceflight, there is a need to understand human functioning and response in a more rigorous theoretically informed way. Current models of human performance in space-relevant environments and human space science are often operationally focused, with emphasis on acute physiological or behavioral outcomes. However, integrating current perspectives in human biology allows for a more holistic and complete understanding of how humans function over a range of time in an extreme environment. Here, we show how the use of evolution-informed frameworks (i.e., models of life history theory to organize the adaptive pressures of spaceflight and biocultural perspectives) coupled with the use of mixed-methodological toolkits can shape models that better encompass the scope of biobehavioral human adjustment to long-duration space travel and extra-terrestrial habitation. Further, we discuss how we can marry human biology perspectives with the rigorous programmatic structures developed for spaceflight to model other unknown and nascent extremes.

  PublisherOA PDFDOI

• Molecular and physiological changes in the SpaceX Inspiration4 civilian crew

  Nature · 2024-06-11 · 55 citations

  articleOpen access

  Abstract Human spaceflight has historically been managed by government agencies, such as in the NASA Twins Study 1 , but new commercial spaceflight opportunities have opened spaceflight to a broader population. In 2021, the SpaceX Inspiration4 mission launched the first all-civilian crew to low Earth orbit, which included the youngest American astronaut (aged 29), new in-flight experimental technologies (handheld ultrasound imaging, smartwatch wearables and immune profiling), ocular alignment measurements and new protocols for in-depth, multi-omic molecular and cellular profiling. Here we report the primary findings from the 3-day spaceflight mission, which induced a broad range of physiological and stress responses, neurovestibular changes indexed by ocular misalignment, and altered neurocognitive functioning, some of which match those of long-term spaceflight 2 , but almost all of which did not differ from baseline (pre-flight) after return to Earth. Overall, these preliminary civilian spaceflight data suggest that short-duration missions do not pose a significant health risk, and moreover present a rich opportunity to measure the earliest phases of adaptation to spaceflight in the human body at anatomical, cellular, physiological and cognitive levels. Finally, these methods and results lay the foundation for an open, rapidly expanding biomedical database for astronauts 3 , which can inform countermeasure development for both private and government-sponsored space missions.

  PublisherOA PDFDOI

• BaYaka mothers balance childcare and subsistence tasks during collaborative foraging in Congo Basin

  Scientific Reports · 2024-10-22 · 1 citations

  articleOpen access

  Across cultures, mothers balance childcare with other labour. Hunter-gatherer mothers face a daily choice of whether to take infants on foraging trips or leave them with caregivers in the settlement, as well as deciding with whom to forage. Yet, it remains unclear how infant presence affects mothers' mobility and food returns during group foraging. Using GPS, heart rate measurements, and food return data from 348 foraging trips by 22 BaYaka mothers in the Republic of the Congo, we found that mothers go on longer-duration foraging trips when they take infants along, compared to when they leave them behind. Despite this, infant presence does not affect mothers' mobility, energy expenditure, or food returns. Mothers also go on longer-duration and longer-distance trips during group foraging, compared to foraging alone. However, they have decreased food returns in larger groups with more adults, possibly due to food competition. Nevertheless, BaYaka mothers maintain their energy expenditure and net food returns in general, regardless of infant presence or group dynamics, likely due to their individual foraging strategies and support from group members. Particularly, children in foraging groups increase mothers' food returns, aligning with women's reports of children assisting as caregivers. These findings provide insights into how BaYaka mothers accommodate childcare with subsistence activities during group foraging.

  PublisherOA PDFDOI

• Evidence for an emotional adaptive function of dreams: a cross-cultural study

  Scientific Reports · 2023-10-02 · 13 citations

  articleOpen access

  The function of dreams is a longstanding scientific research question. Simulation theories of dream function, which are based on the premise that dreams represent evolutionary past selective pressures and fitness improvement through modified states of consciousness, have yet to be tested in cross-cultural populations that include small-scale forager societies. Here, we analyze dream content with cross-cultural comparisons between the BaYaka (Rep. of Congo) and Hadza (Tanzania) foraging groups and Global North populations, to test the hypothesis that dreams in forager groups serve a more effective emotion regulation function due to their strong social norms and high interpersonal support. Using a linear mixed effects model we analyzed 896 dreams from 234 individuals across these populations, recorded using dream diaries. Dream texts were processed into four psychosocial constructs using the Linguistic Inquiry and Word Count (LIWC-22) dictionary. The BaYaka displayed greater community-oriented dream content. Both the BaYaka and Hadza exhibited heightened threat dream content, while, at the same time, the Hadza demonstrated low negative emotions in their dreams. The Global North Nightmare Disorder group had increased negative emotion content, and the Canadian student sample during the COVID-19 pandemic displayed the highest anxiety dream content. In conclusion, this study supports the notion that dreams in non-clinical populations can effectively regulate emotions by linking potential threats with non-fearful contexts, reducing anxiety and negative emotions through emotional release or catharsis. Overall, this work contributes to our understanding of the evolutionary significance of this altered state of consciousness.

  PublisherOA PDFDOI

• Evaluating the buffering role of perceived social support and coping resources against the adult mental health impacts of COVID-19 psychosocial stress: a cross-sectional study in South Africa

  medRxiv · 2023-06-22 · 1 citations

  preprintOpen accessSenior authorCorresponding

  ABSTRACT Objectivesw Growing evidence has highlighted the global mental health impacts of the COVID- 19 pandemic and lockdown, particularly in societies with pre-existing socioeconomic adversities and public health concerns. Despite the sudden and prolonged nature of many psychosocial stressors during the pandemic, recent studies have shown that communities utilized several coping mechanisms to buffer the mental health consequences of COVID-related stress. This paper examines the extent to which coping resources and social support buffered against the mental health effects of COVID-19 psychosocial stress among adults in South Africa. Materials & Methods Adult participants (n=117) completed an online survey during the second and third waves of the COVID-19 pandemic in South Africa (January-July 2021), which assessed experiences of stress, coping resources, social support, and four mental health outcomes: depression, anxiety, post-traumatic stress disorder, and bipolar disorder. Moderation analyses examined the potential buffering role of coping resources and social support against the mental health effects of COVID-19 stress. Results Adults reported elevated rates of psychiatric symptoms. Coping resources buffered against the poor mental health effects of COVID-19 psychosocial stress, whereas perceived social support did not significantly moderate the association between COVID-19 stress and adult mental health. Discussion These results suggest that adults in our sample utilized a variety of coping resources to protect their mental health against psychosocial stress experienced during the COVID-19 lockdown and pandemic in South Africa. Additionally, existing mental health conditions and strained social relationships may have attenuated the potential stress-buffering effect of perceived social support on adult mental health.

  PublisherOA PDFDOI

• 27 Measuring Ocular Misalignment by Age at Space Center Houston to Inform Spaceflight Analysis

  Journal of Clinical and Translational Science · 2023-04-01

  articleOpen access

  OBJECTIVES/GOALS: We developed a non-invasive test of ocular alignment (OA) as a measure of otolith asymmetry, which impacts vestibular function. This test has also been administered on commercial astronauts to study the effect of microgravity on vestibular function. We will assess OA test performance in ground subjects, which has not yet been characterized. METHODS/STUDY POPULATION: Subjects were recruited from visitors to Space Center Houston from June to October 2022. Participants wore red-blue glasses in a darkened room and aligned two vertically or torsionally misaligned line segments, one red and one blue, on a tablet. Each subject underwent 11 vertical and torsional trials. The remaining misalignment was used to calculate ocular misalignment. Subjects self-reported demographic and health data. We calculated descriptive statistics and explored the distribution of overall vertical and torsional OA and distributions by age. Next steps will establish the reliability of the outcome measures with intraclass correlation coefficients and analyze associations between demographic variables and health status with OA performance using linear regression analysis. RESULTS/ANTICIPATED RESULTS: A total of 143 participants (67 female) with a median age of 21 (range 5-74 years old) completed OA testing. Of participants, 64% identified as white, 10% as black, 14% as Asian, 3% as Native American, and 8% as unknown. This test battery was feasible to implement in this mixed-age sample, with a 95% completion rate. Median absolute vertical OA was 0.08 degrees (IQR = 0.17 degrees), and median absolute torsional OA was 0.80 degrees (IQR = 1.20 degrees). Visual analysis of plots of OA by trial number reveals no apparent learning effect within subjects, though some individuals had considerable variation in performance. Average absolute vertical ocular misalignment increased modestly when plotted by age (fitted regression line b = 0.0032 degrees per year of age, p = 0.004), unadjusted for potential confounders. DISCUSSION/SIGNIFICANCE: Ocular alignment testing was feasible in a mixed-age general population sample. Our findings will expand understanding of how OA varies with age. These results will be used to create a normative database to compare and inform analysis of OA results from commercial spaceflights, which include individuals of varying age and health statuses.

  PublisherOA PDFDOI

• Hormone physiology and sleep dynamics among BaYaka foragers of the Congo Basin: Gendered associations between nighttime activity, testosterone, and cortisol

  Hormones and Behavior · 2023-09-01 · 1 citations

  article
  PublisherDOI

Frequent coauthors

• Lee T. Gettler

  University of Notre Dame

  51 shared

• Sheina Lew‐Levy

  Durham University

  31 shared

• Adam H. Boyette

  Max Planck Institute for Evolutionary Anthropology

  26 shared

• Valchy Miegakanda

  Laboratoire National de Santé Publique du Congo

  19 shared

• Jennifer Burke Lefever

  Families USA

  15 shared

• David R. Samson

  University of Toronto

  13 shared

• Patty X. Kuo

  University of Nebraska–Lincoln

  10 shared

• Mark Shelhamer

  Johns Hopkins University

  9 shared