Title:Effects of ad libitum Free-Choice Access to Freshly Squeezed Domestic
White Asparagus Juice on Intestinal Microbiota Composition and Universal
Bio-Markers of Immuno-Metabolic Homeostasis and General Health
in Middle-Aged Female and Male C57BL/6 Mice
Volume: 22
Issue: 4
Author(s): Darab Ghadimi*, Sven Olaf Frahm, Christoph Röcken, Michael Ebsen, Andreas Schwiertz, Regina Fölster-Holst, Wilhelm Bockelmann and Knut J. Heller
Affiliation:
- Department of Microbiology and Biotechnology, Max Rubner-Institute, Hermann-Weigmann-Str 1, Kiel D-24103,
Germany
Keywords:
Asparagus, dysbiosis, microbiome metabolites, short-chain fatty acids (SCFA), polyphenols, bifidobacteria.
Abstract:
Background: Asparagus contains different bioactive and volatile components including pyrazines,
sulphur-containing compounds, and polyphenols. Asparagus juice is a new low-calorie LAB-containing natural
juice product, the usage of which is expanding. Pyrazines and sulphur-containing compounds are degraded by
bacteria on one hand, but on the other hand, dietary polyphenols prevent human colorectal diseases as modulators
of the composition and/or activity of gut microbiota. However, the utility of these asparagus compounds
for reversal of age-associated microbial dysbiosis and the immunometabolic disorders that dysbiosis incites
body inflammatory reactions was not much explored so far. Hence, using middle-aged mice, we conducted the
current study to verify the effect of freshly squeezed domestic white asparagus juice on the biomarkers reflecting
immuno-metabolic pathways linking age-related dysbiosis and metabolic events.
Materials and Methods: Thirty-two conventional Harlan Laboratories C57BL/6 mice aged between 11-12
months were randomly divided into two groups (n=16). Mice in control group 1 received sterile tap water. Animals
in group 2 had 60 days ad libitum free-choice access to sterile tap water supplemented with 5% (v/v) freshly
squeezed domestic white asparagus juice. Clinical signs of general health, hydration, and inflammation were
monitored daily. Caecal content samples were analysed by qPCR for microbial composition. Histology of relevant
organs was carried out on day 60 after sacrificing the mice. Universal markers of metabolic- and liver function
were determined in serum samples. Caecal SCFAs contents were measured using HPLC.
Results: Overall, no significant differences in general health or clinical signs of inflammation between the two
groups were observed. The liver to body weight ratio in asparagus juice-drank mice was lowered. The qPCR
quantification showed that asparagus juice significantly decreased the caecal Clostridium coccoides group
while causing an enhancement in Clostridium leptum, Firmicutes, and bifidobacterial groups as well as total
caecal bacterial count. Asparagus juice significantly elevated the caecal contents of SCFAs. Enhanced SCFAs
(acetate, butyrate, and propionate) in mice receiving asparagus juice, however, did coincide with altered lipid
levels in plasma or changes in the abundance of relevant bacteria for acetate-, butyrate-, and propionate production.
Discussion: To the best of our knowledge, this is the first study aiming at evaluating the effect of freshly
squeezed German domestic white asparagus juice on universal markers of metabolic- and liver function in middle-
aged mice and the role of gut microbiota in this regard. The effectiveness of asparagus juice to improve
metabolism in middle-aged mice was associated with alterations in intestinal microbiota but maybe also due to
uptake of higher amounts of SCFAs.
Conclusion: Hence, the key signal pathways corresponding to improved immune-metabolic homeostasis will
be an important research scheme in the future.
