# Evaluation of Probiotic Growth in Microenvironments Sculpted with Different Geometries

## TL;DR

This study explores how different microstructure geometries affect the growth of common probiotic bacteria, showing that specific shapes can enhance bacterial development.

## Contribution

The paper introduces biocompatible 3D microstructures fabricated via two-photon polymerization to study and enhance probiotic growth.

## Key findings

- Bacteria grew preferentially in protected microstructures with 5 μm spacing.
- Circular and rectilinear geometries supported bacterial growth over 36 hours.
- Microstructures acted as accelerators for probiotic development.

## Abstract

Probiotics benefit their host, potentially exerting microbial
balance
by stimulating the increase in beneficial bacteria in the intestinal
environment. Some studies have shown that specific probiotic strains
can alleviate symptoms of medical conditions such as Alzheimer’s,
reduce the action of carcinogenic agents, and control various biomarkers
in women in the first half of pregnancy. In this context, it is important
to determine the fundamental aspects of probiotic growth to develop
more efficient delivery mechanisms in pharmaceuticals or foods. Miniaturized
biomimetic environments can be useful for that purpose. In this way,
we manufactured biocompatible three-dimensional platforms using two-photon
absorption polymerization to study the growth of a pool of bacteria
composed of Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus paracasei, and Bifidobacterium
lactis, commonly used in commercial probiotics. The
microstructures were fabricated using an acrylic resin employing 100
fs pulses from a Ti:sapphire laser. It was possible to manufacture
biocompatible structures for probiotic development, demonstrating
that microstructures serve as accelerators for bacterial growth. We
evaluated the growth of bacteria in the environments over more than
36 h, giving all conditions for their development. Furthermore, it
was observed that bacteria grow into structures with distinct geometries
(circular or rectilinear) but tend to develop preferentially in protected
environments with spacings on the order of 5 μm.