Summary of PI Amanda Thompson’s study on immune development and gut microbiome in Galapagos

Introduction: GSC Researcher Amanda Thompson, based at the University of North Carolina at Chapel Hill, along with three other collaborators, published an article about human health in Galapagos in the American Journal of Human Biology on December 28th, 2018. The title of the article is “Pathways linking caesarean delivery to early health in a dual burden context: Immune development and the gut microbiome in infants and children from Galapagos, Ecuador.” This publication is based on two studies coordinated with the Hospital Oskar Jandl and the Ecuadorian Ministry of Public Health.

Research question: Women and doctors worldwide are opting for caesarean births, and Galapagos is not an exception with between 36% and 45% babies born this way[1]. But what are the long-term health effects of caesarean births compared to vaginal births?

Several international studies have linked term caesarean births to the risk of allergy and asthma[2], early diabetes[3], and inflammatory bowel disease.[4] The results of these studies suggest that a vaginal birth stimulates a baby’s immune system, helping him or her to meet the world stronger and more adaptable than the caesarean alternative, at least in the short-term.[5] To understand longer term effects, complementary factors like breast-feeding, nutrition and environmental exposures are important to analyze as well, especially when most studies have been conducted in the United States of America (USA) and other countries with similar public health conditions.[6]

Thus, Amanda and her colleagues designed their research project in Galapagos, Ecuador where residents have a dual burden of infectious disease and the highest obesity rates in Ecuador (influenced by water quality and processed foods intake)[7] but also a positive breastfeeding trend: most mothers initiate breastfeeding and nearly 44% infants are exclusively breastfed up to 6 months of age. [8]

The research team asked the question: How are babies and children affected by caesarian births in the Galapagos Islands in the context of a dual burden of disease and positive confounding factor of almost universal breast feeding?

Hypothesis: Amanda and her colleagues from UNC, Kelly Houck and Johanna Jahnke, tested two possible links between how babies are delivered and their health later in life. The first potential pathway is a less effective immune system to fight off illness and the second potential pathway is gut flora in our gastrointestinal track. Their hypothesis was that findings in Galapagos would differ from international trends found in similar research conducted in the USA because of the high levels of breastfeeding and environment of the Galapagos.

Methods: The team worked with local community members to collect data from 41 babies and toddlers and 135 young children (under 11 years old) across two studies from 2014 to 2016 to compare immune system health (morbidity: how often they get sick alongside C-reactive protein, a  response to infection ) and gut microbiota (composition of healthy and harmful bacteria). Specifically, they took blood spot samples to measure C-reactive protein, which is a protein produced by the liver and an indicator of inflammation from infection. They asked mothers to collect stool samples to analyze DNA of the bacteria present to extrapolate gut health. The team applied a survey to measure birth mode, breastfeeding, bathing mode and infant formula use (exposure to water), exposure to illness, nutrition among other variables.

Results: Of the study sample, 57.5% of infants and 47.4% of children had caesarean births with 72% of mothers reporting planned operations. All children received breastmilk for at least 15 months, regardless of their birth mode, showing universal access to a positive factor for pediatric health. The research team ran linear and logistic statistical regression models controlling for nutritional and pathogenic exposure related to age to see if the difference between results by birth mode were due to chance or statistically significant.

They found the two indicators of immune system health, the first potential pathway, were not significantly different between birth delivery mode. However, the types of bacteria in the gastrointestinal systems, the second potential pathway, were notably different, even after adjusting the data for environmental exposure by age.

The research team explains in the article, “Importantly, we found differences in bacterial groups associated with immune development, healthy gut function, and weight gain, and these differences mostly persisted when controlling for nutritional and pathogenic environmental exposures.”

Conclusions: These results support past research finding delayed healthy gut development in infants and children born through caesarian. Delayed healthy gut development is evidenced by more Firmicutes (commonly found in obese people) and less Bacteroidales (important actors in gut health). The presence of these bacteria could lead to future obesity and a compromised immune system.[9] In addition, the research team found that positive factors like breastfeeding do not significantly influence the outcomes that birth modes have on the gut microbiota of babies and children.

Recommendations: The results of this study are preliminary, because few studies have analyzed this research question in country contexts like Ecuador, which differ from the USA and European countries. However, the results demonstrate the need to further analyze the impacts of caesarean births on infant and child health. This information should inform both practitioners and mothers of the consequences of their decision to give birth vaginally or through caesarean in planned circumstances.

You can read the full article at:

Full citation: Thompson AL, Houck KM, Jahnke JR. Pathways linking caesarean delivery to early health in a dual burden context: Immune development and the gut microbiome in infants and children from Galápagos, Ecuador. American Journal of Human Biology. 2019; e23219.


  1. Caesarian birth:The option of physically removing an infant from the womb through a surgical operation. This was initially offered in the medical community as an emergency intervention, but more commonly practitioners and mothers plan a caesarian for different motives.
  2. Dual burden:The condition of a community that has two prevalent health problems that could conflate individual health status.
  3. Gut microbiome:The community of trillions of microorganisms that live inside the human gastrointestinal tract and influence digestion, immunity and even secondary emotions like anxiety and relaxation.
  4. Immune system:The human body´s natural defense mechanism against diseases.
  5. Statistically significant:A mathematical value that the evidence against a null hypothesis is true and thus the research hypothesis could be true.
  6. Vaginal birth:The option of allowing an infant to enter the world through the natural pathway of the human body where s/he comes into contact with mico-organisms through the vaginal canal.

    Freire et al., 2015:

    Kristensen & Henriksen, 2016:

    Cardwell et al., 2008:

    Bager et al., 2012:


    Carrillo-Larco et al., 2015:

    Houck, 2017:

    Freire et al., 2015:

    Magne,etal.,2017: S1471490615002264?via%3Dihub

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In 2022, the Galapagos Science Center (GSC) and the broader UNC & USFQ Galapagos Initiative will celebrate its 10th Anniversary. We are proud to announce the World Summit on Island Sustainability scheduled to be held on June 26–30, 2022 at the Galapagos Science Center and the Community Convention Center on San Cristobal Island.

The content of the World Summit will be distributed globally through social media and results documented through papers published in a book written as part of the Galapagos Book Series by Springer Nature and edited by Steve Walsh (UNC) & Carlos Mena (USFQ) as well as Jill Stewart (UNC) and Juan Pablo Muñoz (GSC/USC). The book will be inclusive and accessible by the broader island community including scientists, managers, residents, tourists, and government and non-government organizations.

While the most obvious goal of organizing the World Summit on Island Sustainability is to celebrate the 10th Anniversary of the GSC and the UNC-USFQ Galapagos Initiative, other goals will be addressed through special opportunities created as part of our operational planning of the World Summit.

For instance, we seek to elevate and highlight the Galapagos in the island conservation discourse, seeking to interact with other island networks in more obvious and conspicuous ways to benefit the Galapagos Islands, the UNC-USFQ Galapagos Initiative, and the world. We will seize the opportunity to further develop the I2N2 – International Islands Network-of-Networks. Further, we wish to highlight and emphasize multiple visions of a sustainable future for the Galapagos Islands and we cannot do this alone. Therefore, engaging the Ecuadorian Ministry of Environment, the Ministry of Tourism, the Government Council of Galapagos, the Galapagos National Park, and local Galapagos authorities, including government and non-government organizations and local citizen groups, is imperative.

The Galapagos Science Center on San Cristobal Island, Galapagos

Borrowing from Hawaii’s and Guam’s Green Growth Program and the Global Island Partnership, we wish to examine existing global programs that emphasize island sustainability and their incorporation into life, policies, and circumstances in the Galapagos Islands. We will also seek to enhance our connections with the institutional members of our International Galapagos Science Consortium and expand the Consortium through the recruitment of other member institutions. We will also work to benefit islands and their local communities by working with citizen groups as well as important NGOs who seek to improve the natural conditions in the Galapagos and diminish the impact of the human dimension on the future of Galapagos’ ecosystems.

Lastly, we will use the World Summit to benefit UNC & USFQ and our constituencies through a strong and vibrant communication plan about the World Summit, creating corporate relationships as sponsors, identifying funding goals through donors, and benefiting our study abroad program for student engagement in the Galapagos Islands. We plan to develop and issue a Galapagos Sustainability Communique after the World Summit that includes the vision and insights of all its participants for a sustainable Galapagos with applicability to global island settings.

We are eager to hear your perspective and have you join us at the World Summit on Island Sustainability!