Lets say you want to adjust the gutter of col for a section of your website. The class no-gutters could be used with the negative margin class mx-n1 and the padding class px-1 added to the col

<div class="row no-gutters mx-n1">
    <div class="col px-1">
    </div>
    <div class="col px-1">
    </div>
</div>