Kristin Keller

Dr. Kristin Keller

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
12 April 2023 in Nutrients
Verified
Journal Article
Open access
PDF file
Noelia Ureta-VelascoNoelia Ureta-Velasco
Noelia Ureta-Velasco
KKKristin Keller
Kristin Keller
DVDiana Escuder Vieco
Diana Escuder Vieco
JFJAVIER FONTECHA
JAVIER FONTECHA
MCM. Visitacion Calvo
M. Visitacion Calvo
CPCarmen Pallas-Alonso
Carmen Pallas-Alonso
Women of childbearing age in Western societies are increasingly adopting vegetarian diets. These women are sometimes rejected as milk donors, but little about the composition of their milk is known. The present study aimed to compare the intake, nutritional status, and nutritional composition of human milk from omnivore human milk donors (Donors) and vegetarian/vegan lactating mothers (Veg). Milk, blood, and urine samples from 92 Donors and 20 Veg were used to determine their fatty acid profiles, as well as vitamins and minerals. In a representative sample of both groups, we also determined the lipid class profile as a distribution of neutral and polar lipids, the molecular species of triacylglycerols, and the relative composition of phospholipids in their milk. A dietary assessment was conducted with a five-day dietary record (while considering the intake of supplements). We highlight the following results, expressed as the mean (SE), for the Veg vs. Donors: (1) Their docosahexaenoic acid (DHA) intake was 0.11 (0.03) vs. 0.38 (0.03) g/day; the plasma DHA was 0.37 (0.07) vs. 0.83 (0.06)%; and the milk DHA was 0.15 (0.04) vs. 0.33 (0.02)%. (2) Their milk B12 levels were 545.69 (20.49) vs. 482.89 (4.11) pM; 85% of the Veg reported taking B12 supplements (mean dose: 312.1 mcg/day); and the Veg group showed no differences with Donors in terms of total daily intake or plasma B12. (3) Their milk phosphatidylcholine levels were 26.88 (0.67) vs. 30.55 (1.10)%. (4) Their milk iodine levels were 126.42 (13.37) vs. 159.22 (5.13) mcg/L. In conclusion, the Vegs’ milk was shown to be different from the Donors’ milk, mainly due to its low DHA content, which is concerning. However, raising awareness and ensuring proper supplementation could bridge this gap, as has already been achieved for cobalamin.

7 August 2023 in Nutrients
Verified
Journal Article
Open access
PDF file
Noelia Ureta-VelascoNoelia Ureta-Velasco
Noelia Ureta-Velasco
AMAdriana Montealegre-Pomar
Adriana Montealegre-Pomar
KKKristin Keller
Kristin Keller
DVDiana Escuder Vieco
Diana Escuder Vieco
JFJAVIER FONTECHA
JAVIER FONTECHA
CPCarmen Pallas-Alonso
Carmen Pallas-Alonso
The influence of the diet and nutritional status of milk donors on the nutritional composition of donor human milk (DHM) is unknown. The present study aimed to determine the nutritional profile of DHM and the associations between donors’ dietary intake and nutritional status and the micronutrient and lipid composition in DHM. For this purpose, 113 donors completed a food frequency questionnaire, provided a five-day weighed dietary record, and collected milk for five consecutive days. Nutrient determinations in donors’ erythrocytes, plasma, urine, and milk were performed. Multiple linear regressions were conducted for the evaluation of the associations. We highlight the following results: DHM docosahexaenoic acid (DHA) was positively associated with donors’ plasma DHA content and donors’ DHA intake (R2 0.45, p < 0.001). For every 1 g/day DHA intake, an increase of 0.38% in DHA content and 0.78% in total omega-3 content was observed in DHM (R2 0.29, p < 0.001). DHM saturated fatty acids were positively associated with erythrocyte dimethyl acetals, plasma stearic acid, trans fatty acids intake, and breastfeeding duration and negatively associated with erythrocyte margaroleic acid (R2 0.34, p < 0.01). DHM cholecalciferol was associated with plasma cholecalciferol levels and dairy intake (R2 0.57, p < 0.01). Other weaker associations were found for free thiamin, free riboflavin, pyridoxal, dehydroascorbic acid, and the lipid profile in DHM. In conclusion, the diet and nutritional status of donors influence the fatty acid profile and micronutrient content of DHM.

14 October 2022 in Nutrients
Verified
Journal Article
Open access
PDF file
Noelia Ureta-VelascoNoelia Ureta-Velasco
Noelia Ureta-Velasco
KKKristin Keller
Kristin Keller
DVDiana Escuder Vieco
Diana Escuder Vieco
Jose SerranoJose Serrano
Jose Serrano
NGNADIA GARCÍA-LARA
NADIA GARCÍA-LARA
CPCarmen Pallas-Alonso
Carmen Pallas-Alonso
Preterm infants are particularly vulnerable to developing iodine deficiency. Donor human milk (DHM) is the preferred feeding option if the mother’s own milk (MOM) is not available, but information on DHM iodine concentration (DHMIC) is lacking. Hence, we aimed to assess DHMIC to further evaluate the adequacy of iodine provision in preterm infants. Finally, associations that might influence DHMIC were studied. In 113 donors, we measured iodine intake by evaluating dietary records for five consecutive days with the DIAL® Software. From the second day of dietary record, donors provided human milk samples (at least one per day) for four consecutive days. Daily human milk samples were analyzed for DHMIC. A DHMIC ≥ 200 µg/L was considered an adequate iodine content for preterm infants. DHMIC and urine iodine concentration (UIC) were determined using ICP-MS. In our study, 83.2% of donors had a full-term infant. Breastfeeding time range was 1.5–49.4 months. During the dietary record, 55.8% took iodine-containing supplements, providing 40–200 µg/day of iodine. The medians (p25, p75) UIC and DHMIC were 112.4 (75.8, 160.1) and 148.5 (97.6, 206.1) µg/L, respectively. In this iodine-sufficient population, 70% had a DHMIC of <200 µg/L. Donors’ intake of iodine-containing supplements was associated with higher DHMIC.

8 April 2024 in Nutrients
Verified
Journal Article
Open access
PDF file
NGNADIA GARCÍA-LARA
NADIA GARCÍA-LARA
DVDiana Escuder Vieco
Diana Escuder Vieco
MCMarta Cabrera-Lafuente
Marta Cabrera-Lafuente
KKKristin Keller
Kristin Keller
CPCRISTINA DE DIEGO PONCELA
CRISTINA DE DIEGO PONCELA
CPCarmen Pallas-Alonso
Carmen Pallas-Alonso
Nosocomial infections are a frequent and serious problem in extremely low birth weight (ELBW) infants. Donor human milk (DHM) is the best alternative for feeding these babies when mother’s own milk (MOM) is not available. Recently, a patented prototype of a High-Temperature Short-Time (HTST) pasteurizer adapted to a human milk bank setting showed a lesser impact on immunologic components. We designed a multicentre randomized controlled trial that investigates whether, in ELBW infants with an insufficient MOM supply, the administration of HTST pasteurized DHM reduces the incidence of confirmed catheter-associated sepsis compared to DHM pasteurized with the Holder method. From birth until 34 weeks postmenstrual age, patients included in the study received DHM, as a supplement, pasteurized by the Holder or HTST method. A total of 213 patients were randomized; 79 (HTST group) and 81 (Holder group) were included in the analysis. We found no difference in the frequency of nosocomial sepsis between the patients of the two methods—41.8% (33/79) of HTST group patients versus 45.7% (37/81) of Holder group patients, relative risk 0.91 (0.64–1.3), p = 0.62. In conclusion, when MOM is not available, supplementing during admission with DHM pasteurized by the HTST versus Holder method might not have an impact on the incidence of catheter-associated sepsis.

5 June 2017 in Nutrición Hospitalaria
Verified
Journal Article
Open access
PDF file
KKKristin Keller
Kristin Keller
SLSantiago Rodríguez López
Santiago Rodríguez López
MMMargarita Carmenate Moreno
Margarita Carmenate Moreno
Association between meal intake behavior and blood pressure in Spanish adults

31 October 2024 in Nutrients
Verified
Journal Article
Open access
PDF file
Noelia Ureta-VelascoNoelia Ureta-Velasco
Noelia Ureta-Velasco
AMAdriana Montealegre-Pomar
Adriana Montealegre-Pomar
KKKristin Keller
Kristin Keller
DVDiana Escuder Vieco
Diana Escuder Vieco
Jose SerranoJose Serrano
Jose Serrano
CPCarmen Pallas-Alonso
Carmen Pallas-Alonso
Background/Objectives: The impact of daily variations in habitual maternal intake on human milk (HM) composition has been poorly studied. We aimed to investigate the associations between day-to-day fluctuation in the micronutrient concentration in HM and daily maternal diet. Methods: To this end, an observational longitudinal study was carried out. A total of 143 lactating women each compiled a five-day weighed dietary record and concomitantly expressed milk for four successive days. Maternal daily intakes of micronutrients and food groups were analyzed. Free thiamine, free riboflavin, nicotinamide, pantothenic acid, pyridoxal, folic acid, cobalamin, ascorbic and dehydroascorbic acids, retinol, alpha- and gamma-tocopherol, cholecalciferol, and calcidiol in HM were determined for each of the four investigated days. A longitudinal data analysis with generalized estimating equation models was performed. Results: For each daily serving of meat, fish, and eggs, total vitamin D3 levels increased by 243.2 pg/mL (p = 0.027) and selenium levels increased by 0.16 ppb (p = 0.031) in HM. For every 1 mg/day of riboflavin supplementation, free riboflavin levels in HM increased by 28.6 mcg/L (p = 0.019). Pyridoxal levels in HM increased by 6.3 mcg/L per 1 mg/day of vitamin B6 supplementation (p = 0.001), and by 2 mcg/L per daily fruit ration (p = 0.016). Conclusions: In conclusion, we were able to quantify the impact of the usual day-to-day variations in the diet and in the intake of commonly used supplements on the fluctuation of vitamin D, free riboflavin, pyridoxal, and selenium concentration in the milk of lactating women.